You might want to get it right so you have the confidence that someone won't challenge you on it. You might want to get it right to be respectful of the culture or to avoid offending someone, but actually, allowing for this shift away from standardization and to a different perspective on dancing, is the more authentic thing.
You see, within raqs sharki/oriental tansi (the Arabic and Turkish names, respectively, for what we call bellydance, both meaning Eastern/Oriental dance), choreography is something that was imported from the west during colonization. That isn't to say no dances in the MENAHT region used pre-set movement patterns, but the social dance, and the dance performed by the awalim and raqassas, this was an improvised art form.
In Arabic performing arts, performing something differently each time is highly valued. Alia Thabit (an Arab-American dancer in Massachusetts) has written extensively about this, including a chapter in her book "Midnight at the Crossroads". You can also see it in the ecstatic reactions of the audience to singers like Om Kalthoom, who would take a 30 minute (as composed) song, and make a 2 hour concert of it by riffing on a line, or even just a word, to milk the emotion from it. Or in a beledi progression, which has a general structure but no set composition because it is played on the musician's feeling. Bellydance is always the music translated into movement, so it shares this quality both as a result of the music being this way, and from the native cultural aesthetic applying to the dance. This is obvious in golden era videos, where the star is improvising and the backup dancers, doing choreography (again, an innovation that Sala owners imported from the West and chose to use in their own way) are each doing the choreography in their own way. This is not because they are unrehearsed or bad dancers, but because it is not their goal to be perfect copies of each other the way the corps dancers in a ballet are striving for.
Traditionally, social dances are learned by kids who grow up doing them. Kids can imitate adults at parties and no one is worried about their technique or if they look a little silly while they learn it, they're kids! Likewise, many dancers who have become professionals talk about how they learned as children from following along with relatives at parties or dancers on their TV .
Imagine you are trying to explain a holiday to someone from another culture. You want to explain how it makes you feel, and the traditions you associate with it. They might ask you why you make chocolate chip cookies for Christmas parties but not for summer festivals, and you don't have a specific reason, its just a taste you associate with the winter season. Likewise, the smell of cut pine might make you crave chocolate chip cookies! This isn't because you were taught to react this way, but over years you just developed an association between the two. I tend to suddenly be in the mood to watch Star Trek Next Generation around bed time, because I have been doing it for a while and just associate it with part of my wind-down routine. Likewise, if you've grown up bellydancing (whether because you were from an awalim family, you mom was a nightclub dancer in Boston, or you just loved to follow along with the dancer or your aunties at family parties) you've likely developed certain associations between what is coming into your ears and what movements you are feeling in your body. For anyone who has learned this way it can be just as hard to explain why they want to do heavy hip drops when they hear the maksoom played a certain way as it is for me to explain why I want chocolate chip cookies when we light up the Yule tree.
For those of us who started learning bellydance after the age of..... say 15, we are behind the ball in developing these associations organically. And for those of us who did not grow up listening to MENAHT music, we have a lot of catch up to do!
I believe there is value in these breakdowns, it helps ease frustration for students, speeds up absorbing a new way of moving and hearing music, and it can give you confidence from knowing what you know, but this way of teaching has its limits. At a certain point, it is on the student to absorb these lessons to the point of no longer needing to think of them.
I also make a point to include follow-along as part of my lessons, I want my students to be able to learn from native dancers whenever they get the chance, even if those dancers haven't decided to adopt more formalized teaching methods. There are native dancers who have studied a variety of pedagogies or who have adjusted how they teach to reach Western students, but others will teach you they way they learned, and we want to learn from them! Both to have direct cultural experience and to support the people the dance belongs to.
Some native dancers teach choreography because it's what western students demand, and by knowing musicality and thinking as much as you can from the cultural perspective of the teacher you can get more out of this experience than just learning a one off choreography. Plenty of native dancers are able and willing to teach in many different ways. But not all are willing to do this, and we Westerners asking to learn an Eastern dance should not expect them to be both sides of the bridge between cultures. Some Western students find this teaching method frustrating, partly because it is unfamiliar, partly because they dislike the uncertainty of not knowing what is coming next, and partly because they aren't sure what they are learning. In terms of trying to anticipate what comes next without a pre-set choreography, I'll say to watch the small of the teacher's back for movement cues, and allow your body to respond. You won't look exactly like the teacher, but this is often the point. Also, allow yourself to be in THAT moment, without worrying about what the next moment will bring. Your brain will process it when it comes, but right now you are processing THIS moment, the next one can wait its turn for your brain-space.
There is a name for all these associations when they build up into a skill set like the one a master dancer has: expert intuition. So, next time you're in a workshop or a class, and the teacher "just dances" while you try to guess what is coming next, realize that you are in fact learning. You are connecting a move to a music type, to a mood. You are learning to link moves and when to change movements. You are developing a subconscious list of options for dancing to different rhythms and instruments. You are learning to respond in the moment and you are experiencing the process of dancing and learning from a new perspective. All of these are incredibly valuable, and worth not just getting through a workshop without complaint, but actively seeking out lessons like this.