unrelatedly I just checked which of the apps on my Mac are 32-bit so I’d know how long to wait before going to Catalina and the unexpected good news is that all the open source stuff like Crawl and UQM and OpenTTD have already been building for x86-64, and the outstanding offenders are:
ck2
Necrodancer
Invisible Inc.
UT2004
Civ 4
obviously I’m out of luck on the latter two as those are like 15 years old (I think they were both originally PPC binaries even, but they got x86 patches at some point, even getting hold of the x86 UT2004 Mac binaries these days is tricky), ck2 seems likely to get patched as they’re still making new DLC for it and Paradox recently patched their newer engines, and iirc Necrodancer actually used some of Klei’s tooling so the two other laggards might also be tied together in some way.
overall still a lousy deprecation but much less bad than I expected.