Glad you're keeping boss battles in some fashion, cause they do be sick!
Adding some Legendaries to the mix also gets that power curve going a little steeper, doesn't it? Part of the complaint against "harder battles" was that the power curve would just get absurd the way things were going, so maybe this will help in giving us both insane fights and the means to beat them.
Personally, I don't really care about being able to catch all mons, especially legendaries. Pick whatever selection you think is appropriate, give em to us as just fights or catches, during the main story, side story or postgame - I'm up for anything.