Well if the "68k" part of 68kMLA is to mean anything, the 68k stuff should get established first. Otherwise let's change our name to "Vintage MLA" or something - which wouldn't necessarily be bad.
That said, I have no objection to including non-68k hardware articles. The name (and theme/atmosphere it creates) establishes our "roots" but c'mon, we all like Apple stuff, regardless of age. If we stay 68k-only forever we'll eventually become an irrelevant, dying niche site. Life is change.
In keeping with the vintage spirit, an arbitrary limit like "nothing produced within the past three years" would not be inappropriate, but no limitation would be OK, too.