Denuvo DRM works on linux however it does require an internet connection and you can get banned for +24 hours if you play on more than 3-5 devices a day (a proton prefix also counts as 1 device).
Yeah I remember trying to debug some issue I had with DOOM Eternal (I think) and then randomly getting the message that I can't play for 24 hours because I'm an evil criminal. Not a great customer experience.