The other misuse that could be avoided by clarifying the description is simple examples of The Verse and Canon Welding turning up on Shared Universe, because people think of 'shared' as in 'shared between works' rather than 'shared between authors'. I might check the wicks to see if it's being used properly.
We're not just men of science, we're men of TROPE!
I think the OP was reading this trope way too narrowly. That said, this is being misused for Cross Overs and such. I actually added the sort of notice mentioned in the crowner, trying to clean up this article a little. One bigger problem, I think, is trying to distinguish actual shared universes with ones put together by fans out of crossover appearances and Epileptic Trees, like the Tommy Westphal universe which is still listed now as an example.