The LC, IIsi and Classic were all released together in the Fall of 1990. It was something of a "low cost" revolution for Apple. Except for the Classic, they were also the first Macintoshes to support 2 MB and 8 MB (not sure LC supports 8) SIMMs. I remember that the magazine articles in MacUser and MacWorld made kind of a big deal about it at the time.

Any Macintosh released before those models does not support 2 MB SIMMs. There weren't that many models after that that still used 30 pin SIMMs, although I guess the Q700, Q900 and Q950 would be notable exceptions.

Anyone know if the first Quadras supported 2MB and 8MB SIMMs?

Ah, Hardware Developer Notes to the rescue. None of the Q700, Q900 nor Q950 support 2 or 8 MB SIMMs.

But apparently the IIvx does support 2MB SIMMs.