Are those Claremont era flashbacks? I have to admit that I went straight to the Lockheed image and haven't read the entire issue just yet. The flashbacks shown in my link above, don't strike me as Claremont specific
I would imagine that they could use Colossus, as it is a Gold side title. Though Colossus is getting his own section of that Memorial issue, so maybe that's why they didn't want to use him