This is a good news for the US citizen. I always saw that there was many restrictions for US citizens to buy cryoto. Now, It will be easier for them to involve in crypto. Crypto market will see many new investors now.
But don't forget that that this move is not totally freedom for them, as you need to go thru KYC, still they are subject to their government's scrutiny if needed. So when they deal with crypto, they still need to make sure that they are not violating any of their government's protocol because they are not totally anonymous with their crypto transactions. But anyway, such move will create more adoption.