Oddbean new post about login | logout well said. I think it comes from people who don't quite understand wine and just want a nod. the only block height that makes sense is the one where the bottle was finished.
I suppose a birth date might make some sense, but wine isn't really the same at any particular point. I could say that the birth is when all necessary components are combined, but the alcohol component isn't there yet (and maybe other chemicals - I don't know the full chemistry). It's a super complicated expectation
This would be a lot easier with Bourbon since it doesn't age after leaving the barrel.