I don't see why he shouldn't. Let's face it, there is literally no one else at 185 that is a threat to Weidman. He beat Silva convincingly in both rounds they fought, it wasn't like it was a first round flash KO. Also, he is undefeated. The trilogy would be huge dollars for the UFC as well.
On top of that Silva has beaten pretty much everyone else at 185 so who and how do they sell Sliva fighting someone else while Weidman has his tune up fight?
I personally think Weidman takes it again. Not necessarily by a KO but more likely the strategy that everyone expected him to win by. A steady diet of takedowns, heavy gnp, and perhaps an eventual sub. Guaranteed he has the skills and the gas tank to do it.
Weidman beats Silva twice, I expect Silva will retire. If you can't be number one after being number one for so long, it's hard to go back to smashing gatekeepers (especially since he is pushing 40). Fedor, Randy, Chuck, they all have to walk away eventually.