The idea is probably to keep listeners tuned in during what they hope is a short delay. Suppose someone tunes in to the game a bit late and hears music or WCBS news, etc. "Ah. Game musta been rained out..." Well, maybe that happens to a few fans.
"You're listening to a rain delay edition of Sox talk..."
(This applies especially to formats like music stations, or talk but not sports talk..people may tune out,
thinking the game's rained out..)
On TV (NESN for example, or TBS with the Braves) they can go to alternative programming but put a graphic
saying "Rain Delay" on the screen (NESN's graphic is fairly tiny though) but not so on radio. WBOQ does
automated music, so no DJ saying "Well, in case you're wondering, the Sox are in a rain delay but in the
meantime we're playing Your Good Time Favorites".
On WCBS at least people will hear, after awhile, "We're in a rain delay at Yankee Stadium and will bring you back
there once the action starts again".
Of course the Red Sox network can also sell spot time during rain delay talk, eh?
WBOQ's going to music shows that affiliates do indeed have control. The board op switches on the computer
or takes a talk show feed off a satellite or something...