Big Tech cloud services (AWS, Azure etc.) have so much CPU horsepower that it is indeed possible to execute a 51% attack against Monero.
We can only speculate because exact numbers are not publicly known, what we know is that current Monero hashrate is so big that making such an attack is in the fairy-tale zone.
I would say such attack isn't profitable, rather than fairy-tale zone. And FWIW, Top 500 list exists.
Bitcoin miners being obligated to government rules (OFAC) is much more likely than 51% attack on Monero.
I think you mean some mining pool located in US,
https://b10c.me/observations/08-missing-sanctioned-transactions/. And i think they'd rather shutdown and sell their BTC rather than helping crashing Bitcoin price.