An interesting find from PRC reader "George:"
According to a very old issue of Game Informer magazine (October 2003), there was talks of a second Anniversay Collection, one that would have compiled the more obscure Classic series games such as MegaMan Soccer and "MegaMan Chess." MegaMan Chess? What?
Of course, an official MegaMan Chess does not exist, but, it's possible the article was referring to Wily & Right's RockBoard, the untranslated "party game" title for the Famicom (pictured).
On another note, the article stated the second collection would have released two months after the first, sometime around April (Ann. Collection was originally slated for a February '04 release but was delayed till June).
Now, I don't know about you, but I would have killed to see a collection of the more obscure MM games, especially an official RockBoard translation.