We ate at 50's last July and again this February. In July, our server was entirely into his act and very fun. He required our boys to set the table, eat veggies, take their elbows off the table, etc. but it was all very fun and good-natured. He pretended he was going to make my husband eat spinach and then broke character in a whisper that only the adults could hear - really funny. We had a great time, we all loved it and we all agreed to add it to our regular rotation.
We were back in February and it was uncomfortable. We were ready for a fun act, but our server's tone was really different and didn't come across as light-hearted. He repeatedly made fun of our pre-teen for ordering from the children's menu - called him a "baby," told him he was never going to have a girlfriend ordering chicken nuggets, etc. He took away our pre-schooler's malt and repeatedly called him a "baby" for not eating his food. Of course, our server could not have known that our pre-schooler has a speech disorder, but he was relentless about telling our son to "talk so I can understand you." Then he told me "no - I'm talking to him" when I tried to help him understand what our son was saying. It had an entirely different tone than in July, but I really believe this is the exception and not the typical experience. All the other servers around us were fun and light, just like the CM last July.
So I think it really depends on the server. If you are concerned, I'd definitely mention something when you check in or directly to your server.