Beat Saber does have a very large amount of patterns, though. If you restrict yourself to the best designed maps, you're likely to find a unique feel to each. It does feel a lot like dancing, although, yes, it's a style of dancing that benefits from your body already knowing the basic positions.
I seem to recall some of the best custom mappers are specifically into dancing/choreography, but don't quote me on this; I don't know how to validate this information (maybe someone from the community will read this and be able to confirm).
I would like to point out we're not questioning whether repetitive activity enhances plasticity but if dancing is better.
Also when the study says dance they mean learning a new dance. If you were to do variations of the same dance over and over this study doesn't prove you would also get the benefits. I'd imagine if we did study it that case would show results very similar to the benefits from repetitive activity.
I seem to recall some of the best custom mappers are specifically into dancing/choreography, but don't quote me on this; I don't know how to validate this information (maybe someone from the community will read this and be able to confirm).