I do consider archdetect.udeb misnamed, as it doesn't deal with "arch"s in Debian sense at all -- even its sources say "subarch" everywhere. Elsewhere the name used is "flavour".
However, it was first. Thus, I think I'll go with "arch-test". Enumerating architectures is something only humans will do for sysinfo reasons, other software will likely call arch-detect/arch-test to query a single given architecture, so "test" should be good. -- A tit a day keeps the vet away.