So this seems like a small distinction for what may be an inconsequential tag, but I have an alias request that's been running on the side and hasn't gotten a lot of attention, and I don't wanna bump the thread.
So according to the wiki for "voice actor joke," the tag is for "Fanart that in some way references the depicted character's (or characters') voice actor(s), usually for comedic effect." The comedic effect part feels like a stretch, and a little presumptive. While there are posts under it intended to make the viewer laugh, there's just as much that only show characters interacting (or fucking) or dressed like another character with no intended punchline. It's the difference between "these characters have the same voice actor. Here's a joke about it" and "these characters have the same voice actor. Neat."
Originally I wanted to alias it to "voice actor reference," but I think "voice actor connection" works better? "Connection" is a more all-encompassing term.