WCBS-AM has not been "all news" for a long time if we're going to split hairs. Prior to the Mets, they aired the Yankees. On weekends they'd clear CBS News Radio programs instead of news. 1010 WINS is exactly what it advertises: all news, all the time.
What you were likely hearing on 1010 WINS were promoted live cut-ins to New York Yankees games (already airing on 660/101.9) for coverage of at-bats by Yankees player Aaron Judge as he was chasing the Yankee and American League home run record. After he hit the record-tying 61st homer on Wed. Sept. 28 in Toronto, it was a while before he hit the record-breaking 62nd homer in Arlinton, TX vs. the Rangers on Tues. Oct. 4th. Thus, there were 5 games + 1 inning of the live cut-ins on 1010.Believe it or not I heard both WCBS and WINS briefly doing sports pbp a week or two ago. Apparently there was an unusual overflow situation. I was going to jokingly post something here about WINS being All news Most of the Time but decided against it because it didn't last long.
When conflicting with Yankees games on 101.9, 660 airs Rutgers college football and NY Giants pro football.
(On occasion, the frequencies are switched around.)
880 is the exclusive radio home of the NY Mets.