Newsday is reporting that the Yankees are close to a deal that would move their radio broadcasts from WCBS to WFAN. This, obviously, would severely and negatively impact the Mets, who've been heard on WFAN since the station's inception in 1987, and at 660 AM since the all-sports station took over that spot in the dial from WNBC in 1988.
The impact of this move (which is far from official) might not seem obvious to everyone in the digital/internet age. After all, you can now stream Mets games via Gameday Audio regardless of who "owns" the broadcast rights. Of course, that presupposes you have a high-speed internet connection, are comfortable using new technologies, and have enough scratch to spend on MLB's digital options. This is not the case for a lot of fans.
WFAN has a famously powerful signal that stretches as far north/east as New England, and can be heard clearly in Philadelphia and points further south. No other New York radio station boasts such a reach, and if the Mets were to be booted off WFAN, whatever signal they land on would be far weaker. Those who still listen to baseball on terrestrial radio in the tri-state area will find the Mets much harder to find. Many may simply cease to bother.
If nothing else, this would be another slap in the face to a franchise that's suffered plenty in recent years.