I agree this is possible in some cases, and I think it gets into the very loose definition of what can count as a “hook”. There are obvious ones, like recruited athletes. But also less obvious ones, like the people who can allow even a smaller college to brag it has students from 49 states (whenever it is not 50, I always think they should be required to disclose the missing states . . . ). I know nothing about music admissions, but it makes sense that could work in a way vaguely similar to athletics. I have heard, with zero objective confirmation, that some smaller humanities departments these days are lobbying to get at least a few possible majors (or at least dual majors, or minors) in every admit pool. And so on.
So, yeah, if you had one or more of these sorts of things going for you, could it help in a marginal case in ED/REA? I can definitely imagine that being possible. But I also think you would have to be very close anyway. I mean, presumably it is often only 49 or 48 or whatever because they just weren’t willing to admit enough people from the missing state(s) to guarantee a yield . . . .
And of course most of their admits are not really like that–they are from states with lots of admits, have relatively common talents, have relatively popular intended majors (or are undeclared), and so on. And all that is fine because in fact many people do get admitted with that sort of profile.
So I do believe what they are saying is mostly true, and true for most applicants. It is just possible in some cases, it is a little less true.
All this is why I personally think rather than strategizing your ED/REA decisions around observed generic admit rates, it makes more sense to do it around perceived fit.
I again know nothing directly about Dance admissions, but given the discussion above if you would love to go to Smith in part because it is a great LAC but also because it seemed like a great school for Dance, then maybe you ED Smith–assuming you do not like another school even better. If Smith is at least a realistic “reach” to begin with, this seems to me like as good a bet as any for “using” whatever ED benefit might even conceivably be available to you (understanding it might not exist anywhere). And then there is no painful downside of wondering if you misused it, since if it works by assumption you will be thrilled.
Or if you are from a state which is in perennial danger of being that 50th state they can’t quite get, why not just ED/REA your favorite realistic reach? It will probably have just as good a chance working there as anywhere.
And so on.