This "situation" regarding Weaver will eventually resolve itself. If he's not effective then he will pitch himself out of the rotation at some point, however if Weaver continues to be average or better he'll finish the season in the rotation which is how it should be.
As far as next year goes, if I were king of the Angels, I'd let his performance dictate whether he should be resigned or not. What I wouldn't do is to let one bad season cloud my judgement on a player that has been an asset to the team for 11 years. If Weaver repeats 2015 then I'd have to say goodbye but I wouldn't make that decision in April. ymmv