It’s not even clear if the Mets are willing to trade Syndergaard, and if they do, you know it’s going to cost the Astros some of their top prospects. Zack Wheeler becomes a free agent next season which may make him the more expendable of the two pitchers. Syndergaard won’t become eligible for free agency until 2022.
Therefore, New York may be more willing to listen to offers that would have less of an impact on the Astros pool of Minor League talent. The downside would be that he might end up just being a short-term rental for Houston.