it's "support" it just means "if the lib doesn't work we didn't do it, it's not supposed to be part of our system, don't use it problem solved".
that doesn't mean they'll take active measures to prevent us from installing the 32bit libraries. I'm sure they're perfectly aware of the wine implications. adding 32 bit mode was already needed since ubuntu 17 when installing wine from wineHQ. the only difference is now we can't complain to them if they don't work, we'll have to fix it ourselves.
and don't think we personally need to worry about it since we're using proton and I'm sure steam sees their steam play's continued functionality as a priority.
and a vast majority of games that require emulation on linux are 32bit. 64bit games are still quite rare and new.