You know? That might have been the case. I was an old Google Music subscriber, and I think when that rolled over to YT Music the subscription package bundled in YouTube premium. Later when I bit on the Google One subscription later, I think it was on a promotional offer. I remember it was about $100 at the time, and it aligned with some storage needs U had so why not?

I just looked and it seems the Google 1 and YT sub’s are billed separately. It was a while ago and my memory is hazy, but I’m into Google services for about $30 a month these days, and that’s what I pay for.