My annual Apple Music subscription lapsed for one day, and my entire library was gone the next day when I resubscribed for another year.
Apple are allowed to make whatever customer hostile choices they want. As a former Apple Music customer, I’m not making that mistake again.
Playlists are basically zero cost to store. You would spend more $ on delete processing than keeping them around for eternity. So it's just not well thought use-case, implemented without attempt to view the whole picture.
Erasing a music app data after just a couple of months is idiotic, even more for a company with such deep pockets like Apple.
My account is still there. I can still use it. I am pretty sure it has some historic data there as well. Probably my old lambdas are still laying around.