What have 20 years old scanners to do with anything?

Bitness of the software packages is about application support, not the hardware.

And SANE is the linux api for scanners, that's it. Of course there is hardly any native 32-bit-only software nowadays, but of course wine is always the major reason.

And until wow64 is actually the default (but even then really what's the harm?) I don't see why all this haste with dropping this.