The issue has been raised in https://community.ubuntu.com/t/poll-will-dropping-the-i386-repos-affect-your-use-of-the-amd64-port/11290
Some printer drivers are shipped as 32 bit debs. Random example on
https://support.brother.com/g/s/id/linux/en/download_prn.html
Looking to the first in the list (DCP-110C) the deb has no depends (seems to be a convert from a rpm), it includes a library
$ ldd ./usr/lib/libbrcompij2.so.1.0.2
linux-gate.so.1 => (0xb77ba000)
libgcc_s.so.1 => /lib/i386-linux-gnu/libgcc_s.so.1 (0xb76a7000)
libc.so.6 => /lib/i386-linux-gnu/libc.so.6 (0xb74f1000)
/lib/ld-linux.so.2 (0xb77bb000)
Those libraries will keep being available as libc6-i386 and lib32gcc1.
So in theory that driver should still be installable and working even without an i386 archive.
That said, does anyone know how those drivers are working today? Is system-config-printer setting multiarch for the user to be able to install/use those? Does cups has some multiarch glue to load i386 drivers?
@till-kamppeter can you provide some input there?