Yeah,
it came in at some point in the middle of last year. I remember hearing about it, but not being too fazed about it as I thought most teams probably didn't have more than 13 pitchers, maybe 14.
EDIT: And reading that article now I see I was wrong. 18 teams had 14 at the time while 1 had 15. Well, I'm glad they finally do it. I remember back when we had 25 man rosters I thought teams shouldn't have more than 12, maybe 13 pitchers.
EDIT2: FWIW, I just tested it with a new MLB2023 league and OOTP24 is usually, but not always, following it. So I reported it. I'm sure they'll get to it soon.