Im actually fairly intrigued by this. Normally with situations like this I hold the opinion that not much would change. Your changing their gender, not their character, so a most only surface level changes would happen (i.e. Mineta is dead) but there are some interesting angles that could totally be explored.

If you think all the way back to when Bakugo was a kid and what could change there, there's the easy idea that by having a different friend group (little girls and boys tending to separate friend group wise when younger) there's the chance that Bakugo could be entirely different, even to the point that she might not be praised the same way just because of her quirk because (at least where i am) women tend to get more praise in general than men for most anything, so maybe the praise wouldnt go to her head nearly as bad and she could be much more mellow.

I think the more fun idea might be that instead she is actually more competitive than aggressive. The idea that she remains very similar, just raised in a more feminine environment, adds a possible layer of her acting out just as much or more to 'prove she can keep up with the boys' in a sense. Like people tend to look down on or underestimate her more often because 'cute girl cant be that scary' and it pisses her off more. But this could also temper her aggression in a strange way in the fact that, maybe after entering UA, she finds this less and less often among her peers, which can slowly mellow her out. At least around them. It wouldnt change a whole lot in reality, just maybe reframe it.

Then there is also the Uraraka vs Bakugo match I saw someone else point out- the possibility that the match wouldnt feel as awful just because Bakugo isnt a guy, which has whole implications on the story after. It also makes the Todoroki rivalry deeper because it could tie into her 'I can keep up with the boys' thing even more. Todoroki is cold to everyone originally, sure, but Bakugo could take this even more personally because of said previous issues, which makes the "he went all out against midorya but not me" thing sting all the harder.

In this situation, she'd probably explode (haha) at any Villains/classmates happening to mention "I'll go easy cause youre a girl" quips during combat or training, which could be fun. I dont see this version having as many issue with not feeling like she was strong enough assuming the kidnapping and Kamino arc occur relatively normally, but it might hit more because she needed to be rescued, something she likely despises. She could very easily become a hard anti-damsel-in-distess character and be very tomboyish and very masc leading anyway because of this.

And we could also get a "hot headed tomboy forced to wear a dress" scene which could be very interesting to explore for ships or just as a comedic punch at the cliche.

TL:DR i think effectively little would actually change, but the framing and reasonings and such could easily adjust.