If KYC gets mandatory, we'll probably see a bit drop in the number of users adopting crypto (maybe because their sole intention of using it is remaining anonymous while trading and gambling it, but if such rights will also be taken away from those users, I don't think people would use exchanges but may go more for things like uniswap and p2p).
I don't think so. As much as I constantly espouse privacy and decry KYC, I am under no delusion that the majority of people involved in bitcoin today do not share my mindset. Further, if someone is looking to get involved in crypto solely to remain anonymous, then monero is probably a better choice for them than bitcoin is. And if they do want to use bitcoin and remain anonymous, then using a centralized exchange, even without completing KYC on it, is a terrible choice.
If KYC becomes mandatory, then we will likely see a proliferation in the number of DEXs and a growth in the volume they are dealing with, which would be great for everyone who is interested in their privacy.