@Vroom I just checked and DCU has all the Armageddon Annuals except for
Superman, Batman, Justice League America, Action Comics and Justice League Europe.
It should be noted that the Justice League Europe Annual is written by Gerard Jones and not trying to drag that issue out again, but it would make it likely that one won’t appear on here or comixology any time soon. Unfortunately the JL Europe one was the only annual to really have any true tie into to the series, as it lead directly into Armageddon 2001 #2, but still not really a necessary read to follow the story.
But given they added the mini-series I could see them adding the other annuals in the near future to the library. It is one of the few crossover events they have that is missing so many of the tie-ins. Especially since the ones in question are Superman, Batman and Justice League titles. So not like these are from lesser known books… hell the lesser known titles ironically all have their Armageddon issues.