PUBG is currently a game that doesn't work at all on Linux due to anti-cheat, even with the Steam Deck coming it's sounding like a game that won't play nicely. Oh, it's also going free to play.
In their development letter posted on December 10, they outlined what they've been doing and their future plans for anti-cheat with PUBG. While previously PUBG relied on BattlEye, which does have Linux support and recently made it easy for developers to turn on support for Proton and the Steam Deck, their newer proprietary solution with Zakynthos is going to get more invasive and cause more problems.
Through 2022, they explained that one of the major adjustments coming would be the "Implementation of kernel drivers" and I'm sure I don't need to explain to any regular Linux gaming fans why this will be a problem. These kernel drivers are designed for Windows, and something Wine / Proton likely will just not work with.
So what's the hope for PUBG running on Linux / Proton and the Steam Deck? It's not looking good.
A shame, as it's consistently in the top 5 most played games on Steam.