I did receive an upgrade, balloons, a gift, and a card when we stayed at the Contemporary for our 10th anniversary.
My daughter didn't recieve anything when we stayed at the BWV over her 3rd birthday. (same trip)
I would feel uncomfortable telling the hotel staff we were celebrating a special occasion, it would feel like we were asking for something, that's just me.
The only reason we received what we did for our anniversary is because the man at CRO taking our ressie was very friendly, talkative, asked me if we were celebrating any special occasion, or if we were down there just for vacation, etc etc etc. I never gave it another thought and was SHOCKED that we recieved anything. Pleased, but shocked.
On the flip side, my daughter not recieving anything for her bday didn't bother me at all.