Who says they're supposed to have leverage? There's only one country station in Buffalo too. Where does a country DJ go if he loses his gig? Another format or another market. That's what usually happens. Lots of former Buffalo talent have done it, often to their advantage. The idea of spending one's entire career in the same market isn't typical or guaranteed.
As for Rush, he should be used to this by now. Even at iHeart-owned stations, he's been getting moved from stronger to weaker signals all over the country. It could happen in Buffalo. But realistically, if Bauerle is going to be syndicated beyond Buffalo, it won't be in the daytime. He'll be on a lot of stations at a time when no one is listening.
Let me ask this: Where on earth would Limbaugh go in this market if WBEN dropped him? When it comes to talk, they're the only player in town.