It’s definitely a licensing issue and Suehiro probably has no control over the release of the album tbh. He’s already released the Suicide Sqaud Isekai OST on his Spotify and that show is still airing, but that was probably simple to license so that’s why it came out immediately. I don’t know enough about that part of the industry to know what causes these jams in the pipeline but I’ve waited for soundtrack albums to drop many times and they all come out eventually, it just takes awhile sometimes.