People on reddit are absolutely losing their minds over the lack of steam workshop support, but if Paradox wants stuff to be available to console users and all PC users, it's really the only option.
My concern is how it'll interact with Steam Proton on Linux, and just generally if their mods platform will be any good.
My experience with modding games while using Proton on Linux (without Workshop support): It's atrocious, cumbersome and even outright does not work for some games because communities tend to build a Mod Manager (that then other mods start to hard depend on) that does not work in that environment at all. I'm at the point where I don't even bother trying it out if there's not workshop support.
Paradox's first party titles generally have excellent Linux support and have for a long time. Can't swear that will be the case here but overall they're one of the best publishers for Linux.
The way those mod loaders work for games that don't have built in mod support is often by using Win32 APIs to inject the loader into the game process like a virus. It's unlikely that injection mechanism and subsequently finding the relevant game code works correctly on Linux under Wine. Mod loaders that involve modifying the game files or placing extra DLLs in the game directory might work, but might take some extra tricks.
Bummer to hear it's not using Steam. After seeing Bethesda screw up modding with Creation Club, I have low hopes for Paradox's attempt, considering they already monetize the shit out of their games.
Some people with early access have been playing on computers below the reccomended specs and been okay. Teddy Radko has a 3060 and i7-4770 and is getting good enough performance.