So I was talking to an Argentinian teacher recently, and she said that the leader chooses the style of the dance. Close embrace, open embrace, or dynamic... flashy or not flashy. The leader chooses based on what they feel in the music, and the style which THEY are most adept at. When you are dancing, you are supposed to give the follower your best. If your partner doesn't like your best, then you find one that does.

You can't please everyone.
I would like to point out that this is to be read as a whole, the first phrase « the leader chooses the style of the dance. Close embrace, open embrace, or dynamic... flashy or not flashy. » is explained by the following phrase « The leader chooses based on what they feel in the music, and the style which THEY are most adept at. »
« the style which THEY are most adept at »
So this is not an arbitrary choice but a matter of skills.
If a leader is crap at close embrace and good at open embrace, and the follower has a preference for close embrace, does she still prefer this leader to try to dance in close embrace? If this is the case, why not. But if the leader dances in a way he is good at, he will be more able to adapt to the follower.
It's a bit like the situation between an advanced leader with a beginner follower and a beginner leader with an advanced follower, isn't the first one a better case?
« The leader chooses based on what they feel in the music »
I find that the leader's responsability in music interpretation is greater in AT than in other dances (where at worst you can just do a sequence of moves, and where the moves have a preset timing), the music will shape the dance and the dance will feel better if it matches what the leader feels in the music (because the leader has to choose what and how, direction, amplitude, speed, acceleration, timing, etc…).
Sometimes if not much inspired by the music, I would like to tell my partner, hey let's exchange roles take the lead in music interpretation and I will try to follow your proposal.
Of course there is also the feel (through the connection) from and with the partner and it feels better if the two « sont sur la même longueur d'onde » (litt. « are on the same wavelength ») (translation?
Angel HI?), « en phase », so you will try to achieve that.
« flashy or not flashy »
Don't forget the other couples on the dancefloor, and you don't dance AT to show off, do you? Or maybe your partner doesn't want to show off.
And I'm not sure technical ability and musical interpretation need "flashy", so if one partner doesn't wish "flashy" don't go for it.
I see dancing with someone as an agreement, something two persons agree to do together (and which is supposed to have a positive effect on each), so I also see the initial choice of embrace as an agreement.
I think that leading and following are two different roles but of equal stature, there might be reasons hinted above to let some choices to the leader, but why not learn both roles and exchange them from time to time?
« If your partner doesn't like your best, then you find one that does »
Somehow I read this phrase as « If your partner doesn't like your way of dancing, then you find one that does », it's not that you don't care about what the partner likes and don't try to adapt to it, but why not try to find someone who is pleased to dance with you the way you feel to dance?