According to Neil Best, the Mets are "likely to remain on WFAN" past this season.
From Best:
If the Mets had left, WFAN simply would have inherited the Yankees from its CBS Radio sister station, WCBS-AM. It is not clear where the Mets would have landed if they had left the FAN.Maybe someone with the Mets is reading my blog. Maybe they were exploring their FM options. Maybe I'm crazy.
I love WFAN, so I can't complain too much. But this does mean I have to listen to more Wayne Hagin. Great.