You really should go in there with the attitude that this is a regular place to eat and nothing happens. It is not really a themed party or anything like that. There are more than a few of the CM's at WC that do not do anything but wait on tables like any other waiter would. A few CM's do put on a "show" or interact with the guest. Lots of guest think that they are supposed to get entertained at WC. They report back here that they did not, and that their CM's was terrible. The CM's are only supposed to wait on you, not act silly. If you get a silly one, then it is a bonus for you. The management ot WC allows their CM's to act silly with guest, but it is not a requirement to do so to work there.
Also, the CM's that do the gags can not do them for everyone. They may do the ketchup routine once ot twice during your dinner. It would be stupid if they did it for everyone, and would not be funny. If a gag has already happend, don't try to ask for it. Try to egg them on with something else.
There are too many post here of guest see the ketchup gag at the table next to them, and then they ask for some, only to get a bottle. They become upset and offended. That is not how gags work. it is supposed to be unexpected.
It is a great place, and 1 of my favorites. I think the nachos are the best in WDW. The people that give it bad reviews for the most part is because the expected to have practical jokes played on them and did not get it. they lacked the sence of humor to enjoy it played on another table but not their own. They do not understand how practical jokes work.
There is also many things that happen for the whole restaurant to take part in. So no one can usually say that there was nothing fun taking place, because they could have participated in the song, or whatever it is.