As it turns out, the idea that the robots would be restored to goodness was part of the first Rockman story, long before Ariga's or Ikehara's mangas came about. Having to collect those chips from the 6 RM1 bosses dropped wasn't just to gain weapons but to recover the hearts and minds of the robots themselves. We never did see that plot element come to full fruition in-game until later on though.
I dont think many folks knew that though. they figured thats how Megaman got the weapon. And certain appearances elp to blur that, as with Cutman in Megaman 8, and Gutsman in 7. (which, have we ever established whether it is Gutsman or a copy?)
PU was just the first one to actually show the idea in game though.
also, another note on when you mentioned guides, the Command mission guide- is of questionable canonity as well, as it's intro tells of story events but then kind oif has its own story, telling of the events in the firm of a message from Alia to Signas, saying that the Eastern Maverick hunters, (AKA Redips,) is requesting backup from them.
Ill put up the scans later.