Well, the tv series does mention disparate creatures living together, especially in the third episode; something is mentioned about Ruby having to learn the secret of how Littlefoot and his friends live together. I still think that the whole "living together in peace" theme is still on; its just that Charles Grosvenor is going about it in a different way. It should be noted that in his very first LBT movie, he reintroduces Chomper and the whole idea of living together in spite of differences. Of course, Chomper is a Roy Allen Smith character (like Ali.) The closest Grosvenor has come to having a normally dangerous dinosaur live together with herbivores is Ruby, and although she is an egg-eater, she can also eat plants as well, which mitigates the whole situation. I'm sure we will eventually see Ali again; we just have to wait. My personal theory on why it's taking so long is that they want to save her for a series-turning occasion; one that brings the matter of "living together someday" to its conclusion.