Where are they going? To FM, I presume?
If so, they are just mirroring a national trend that has been going on for many years.
The Pittsburgh Pirates were on KDKA for roughly half a century before moving to FM.
At one time that would have been a crazy move, but the team was convinced that the
younger fans (and hence, the future) lay on the FM side of the dial.
Recently the Pirates moved their games back to KDKA, but on the FM side. They are not
on KD-AM, and supposedly told CBS that they don't want their games broadcast on AM in Pittsburgh.
At one time both the Penguins and Steelers had WTAE-AM as their flagship. By the mid-90's though
suburban sprawl had moved beyond the usable signal range of that 5kW station.