1. That's a pretty dubious argument, TS. The only reason there's a "new contract" is that Costa allegedly couldn't make the weight. The fact that he agreed to fight at a certain weight, then wasn't able to make that weight, is obviously unprofessional - especially considering he didn't even attempt to cut the weight. At best, you can say he was unprofessional in not making the originally contracted weight, but he handled the aftermath as professionally as possible.
2. It's still very curious that he didn't even try to make weight. He allegedly weighed 211 pounds a couple days out from the fight. There are other MWs who cut from that range. In fact, Costa himself weighed 214 pounds when he walked into the cage against Yoel. To me, this indicates either: (1) his team lied about his weight, and he was actually heavier than 211 pounds; or (2) he's checked out mentally and simply didn't feel like doing a weight cut.