I have a theory about something that I may have brought up on here back on the old site before the hack attack.
Some years back, there was a claim given on so many wikis (and TV Tropes) that stated there had been an episode of Goof Troop where Goofy had sat down with Max to talk to him about his mother, and that said scene hinted that she was deceased, with Goofy saying "She's up there with the stars" or "She's up there amongst the stars."
That claim is no longer on all these wikis because, a few years ago, I went and corrected them all since there was no such scene in any Goof Troop episode, either of the two Goofy movies, or anything else. It was all hearsay.
That said, the idea of how this hearsay could have started up got me wondering if maybe someone had misremembered a similar father/son scene from another show or movie released during the same 90s/early 2000s era, and could have mentally misattributed it to Goofy and Max.
So I got to thinking about other cartoons/movies from that time that had any single fathers/motherless sons in them, and then I remembered Chuckie and his dad, Chas, from Rugrats. That was definitely a possibility. And then, today, I found Rugrats in Paris playing on Pluto TV, and after giving it a watch, I found this particular scene from 6:04 to 7:00 (apologies for the low video quality):
That heart-to-heart moment between Chas and Chuckie talking about Chuckie's late mother, with Chas even saying "I'll bet she's in Heaven right now looking down on us," feels like a very strong contender for where the "She's up there with/amongst the stars" false memory between Goofy and Max originated from.
And that movie came out in 2000, the same year An Extremely Goofy Movie was released, a movie which contains a scene where Goofy mourns his son's departure to college and grieves over how he is now truly alone (which also likely fueled the belief that Max's mother was dead). Said scene even features Goofy finding his son's old stuffed teddy bear, just as Chas finds Chuckie's old bear in the Rugrats scene in question.
It's very possible that whoever wrote the original claim about the alleged scene between Goofy and Max could have conflated the scene from Rugrats in Paris with Goofy's grief in AEGM and misremembered Goofy and Max having had a similar scene in a Goof Troop episode to the Chas and Chuckie scene from Rugrats in Paris.