No idea why it would tell you to call for CRT - I have booked that with no problem online for years. The only time I call dining is when there is some kind of special situation that can't be done online - ex. booking two ADRs at right around the same time if your party is splitting up and eating in different locations. I have never done Mickey's Backyard BBQ but it comes up as available all the time when I am making my ADRs. I would keep in mind that when you call you have to get through the phone prompts and then the CM spiel. I think online is a MUST faster process and, therefore gives you a better chance of getting what you want.