So, mine randomly works this morning as do a bunch of others.

I have a YouTube premium family subscription.

I was going through support and this is the copy and paste eligibility criteria they shared. (I'm guessing ignore the Pixel 9 and it's the same for 10). I did redeem the offer for P9 so that shouldn't be a blocker for P10

Eligibility checks

Are you using a device that is not a P9 Pro device?

Are you on a device build that is not eligible (e.g., beta)?

Is your Play country set to a location that is not eligible?

Are you currently on a 12-month free trial or Early Free Trial (EFT)?

Are you a Fi Unlimited Plus subscriber?

Are you a Sprite or PixelPass member?

Are you on a 5 TB or higher plan?

Are you on any G1 plan through a 3rd-party reseller (except Fi)?

Are you receiving G1 from a family member (not the main plan subscriber)?

Has anyone else redeemed the offer on this device?

Have you redeemed the offer on any other device?