I don't see Boston leaving Providence for Worcester unless H. Larue Renfroe wants them to since he owns the team. Though if the Sharks leave it would give him an opening since it would be the first time since he got majority control(2006) that a team in Worcester didn't exist and he owns that rink in Marlborough that's just a few miles outside the city. Hmmmmmmm. Might have a great base for a Providence to Worcester rumor here if it wasn't for the fact that Providence is doing much better in attendance though that might be attributed due to affiliation(Bruins v. Sharks).
Boston isn't leaving Providence. Delaware North has a nice concession income there.
Of course there is another elephant in the room as sooner or later the NHL will expand to at least 32.