In a few threads on the Steam forums for an upcoming game called Starbase from Frozenbyte, the developer have spelled out that they believe Valve’s Proton Windows emulation compatibility layer is better than the older ports their games (Trine, Shadowgrounds) had:
Currently it’s probably a better idea to play the Windows versions of our old games via Proton, than trying to get the native versions running.
The majority of Frozenbyte’s games were brought to Linux, but they say it’s unlikely for Starbase unless the Linux audience increases in size:
If Linux gaming takes off (for example, because Steam Deck becomes a huge success), then we’ll have a reason to consider not-so-low-on-resources port, which may (and probably does) change the picture somewhat.
…and they say that another reason to do the port might be if people who play Starbase using Proton report issues:
I recommend using Proton, because it usually just works. If a user reports that Proton no longer works, we would pay attention, but can’t promise anything is done very fast.
These are just comments from an engine developer (Jukka Larja) at Frozenbyte on their game’s forums, so I wouldn’t consider them to be the final word in what gets done, but it seems likely that the statements are accurate and Frozenbyte won’t support Linux in the future if Proton is effective at running their games.