Can it not be done in phases?
Phase one: No new 32 bit programs in repos and open a 64 bit only test branch to identify more pain points.
Phase two: Create a support group to help get 32 bit programs modernised and removing those pain points.
Phase three: Start culling unused packages/libraries.
Phase four: Maybe make 32 bit compatibility opt-in in the installer, and point people toward the aforementioned support group if/when they encounter issues.
Phase five: The eventual removal of official 32 bit support.
Personally I think with the long legacy of 32 bit computing this timeline should be as long and drawn out as feasible but it does have to happen eventually and the sooner it’s started the longer people have to get things sorted out.
Personally, Steam is a dealbreaker for me, as is recording stuff in OBS. I wouldn’t be surprised if there are other 32 bit things I’m dependant on without knowing. I like my experience with Fedora so far, while I know that 64 bit Steam is beyond Fedora’s scope to fix, I’d hate to be forced to another distro on account of this.