My experience is that a 20 year old exe file has a greater chance of running in wine than it would in windows, and a 20 year old Linux executable is going to fail because the shared libraries it depends on are unobtainable
20-year-old exe files can fail on both Windows and WINE if they touch something relatively obscure. It's easier to throw files at the problem under WINE though (you can just throw away the prefix if you break something). The single biggest mistake WINE makes is defaulting to a single shared prefix (and the second sin is similar - trying to integrate folders and menus naively).
20-year-old dynamic binaries on Linux can almost always work today; snapshot.debian.org has all the old libraries you'll ever need. The potential exception is if they touch something hardware-ish or that needs exclusive access, but this is still better than the situation on Windows.
20-year-old static binaries on Linux will fail surprisingly often, since there have been changes in filesystem and file layout.
