Official word from John K's blog, plus the impetus for RnS on the Simpsons:
http://www.blogger.com/comment.g?blogID=22406604&postID=116805677219321914
"No Eric, I like Matt.
We together conceived of the idea to have the Simpsons appear on Ren and
Stimpy and vice versa. Then Nickelodeon took over the show so I never
got to put the Simpsons on Ren and Stimpy, but Matt went ahead and put
Ren and Stimpy on the Simpsons.
Matt didn't work on Boo Boo Runs Wild. I don't know where that rumor
comes from. I think he likes the cartoon though. He has come to watch
that and my other stuff at retrospectives. "
