I think it's pretty likely that they just don't look at or test Newpipe when they change their APIs. If the change doesn't break any official clients, it goes through.
With how large Youtube is, I iimagine API changes are not infrequent.
Well, then a service like Integuru would be perfect for Newpipe! Maybe someone should suggest them to use this awesome service? (I am pretty sure Alphabet would be really happy about that one! :D)
I think it's pretty likely that they just don't look at or test Newpipe when they change their APIs. If the change doesn't break any official clients, it goes through.
With how large Youtube is, I iimagine API changes are not infrequent.