Comment by LorenDB

Probably not unless Apple provides a way to run 32-bit binaries or some really dedicated hacker figures out a way to make it work. Even Valve's own titles have 32-bit macOS versions (e.g. Portal 2) that won't work on modern macOS, so Proton on macOS today would only work with more modern 64-bit games. Not a problem for some people, but Valve really likes to support everything.