Earlier quoted context omitted.
This does nothing to protect anonymity as you are still assigned a unique code that has been tied to your ID at the liquor store.
Historically liquor store checks were purely visual. These days they are often digital, meaning claims about privacy might (or might not) be outdated. The general principle still applies though. The physical infrastructure already exists, the ID checks do not necessarily need to be digitized or recorded, and even if they are the issued tokens don't need to be tied to the check. Grocery stores already sell age restric…
And I don't know how things work in other places, but I've never had my ID scanned when buying alcohol. These days clerks don't even ask me for ID because I obviously appear to be legal age.
In my proposal the token would be a scratch off card with a unique code. It can't be associated with the transaction.