According to Sesame Street Unpaved (the book) - they decided that the Snuffy situation might be giving kids the idea that grownups wouldn’t always believe what kids had to say - therefore abused children might not speak out.
Kinda makes sense - but I miss Snuffy’s poor timing as well!
His death was not mentioned on Sesame Street because he had already left the show by then (in 1989, IIRC.) Someone told me once that his leaving was explained by David sending a postcard the next season that explained that he had to move away from Sesame Street to take care of a sick grandmother or aunt or somesuch. Nice guy, that David!
Now, this was not the reason that Northern Calloway left. It probably was the cancer, but, perhaps it also had something to do with this bizarre tale from The Nashville Tennessean (posted on alt.tv.sesame-street). Apparently, Northern Calloway went berserk in Nashville, Tennessee in 1980 and beat a woman with an iron rod, among other things. When they arrested him, he started screaming, “I’m David of Sesame Street and they’re trying to kill me!”
Maybe that’s when it was decided that Maria and David should “just be friends”.