I haven't used Youtube Premium myself, but I've heard many reports of both ads and promotional crap that gets through to premium users.
I'm also pretty sure that data collection is still on, meaning that you'll get tracked and ads elsewhere (such as on Google.com) based on tracking your youtube premium behavior.
I'm also pretty sure that data collection is still on, meaning that you'll get tracked and ads elsewhere (such as on Google.com) based on tracking your youtube premium behavior.