Gonzales being included in a trade to a rebuilding team for a starting pitcher makes sense. It's common for rebuilding teams to want a major league player at the same position as what they're trading. Even rebuilding teams have to field a complete squad. So I could see the Braves trading Gonzales and either picking up a chunk of the cost or else including a better quality prospect to get the rebuilding team to pick up the cost.
But Gonzales wont be anything resembling a central part of a trade for a starter. The guy has negative trade value, hence us getting Kelenic in the deal. But even so, it makes sense for him to be in a deal for a starter.