Been going there since 1983 and only once have I been "given" anything. Never looked for it, never expected anything, in fact I never even thought about it when I was there.
The first time was last April. My "grown" Daughter's birthday was on the 3rd of April. We were heading home on the morning of her BD, so I had scheduled lunch at the (forget the name now) restaurant inside Mexico at World Showcase two days before our scheduled departure. I left my reservation sheet in our room so I went to Guest Services to see if they could tell me what time my reservation was. They told me and I asked them how much extra it would cost to get a small birthday cake for her. Well, they got all excited and gave me a Birthday pin to give her and said that they would call ahead to the Restaurant. I told them that her Birthday wasn't for another 2 days and it wasn't necessary, but they insisted. The young lady at the counter just smiled and said..."I won't tell them if your don't".
She got the cake and a Mexican version of Happy Birthday plus later in the day she received a Happy Birthday Greeting from Goofy over a phone at the American Adventure plus so many CM's wishing her a happy Birthday. It was great. I didn't ask for it, in fact, I had originally refused it because it wasn't really her birthday yet. That was enough to keep me happy since then.