Remember watching her interview with Robert Osborne on TCM and her relating how bad the MGM clique treated her because she replaced Judy Garland and hard to believe she was not even invited to the premiere!
I'd take that with a grain of salt as Betty was notorious for her victim/persecution complexes. Ever the gentleman, Howard Keel, when questioned about working with Betty Hutton, famously said that she was a less "generous" performer than Judy had been. I would hazard a guess that, if people at MGM didn't "like" her, it had more to do with her own behavior than any loyalty to someone who was removed from the film five months prior and never coming back, no matter what.
As regards the "premiere" story which has gained a lot of traction since the Osborne interview, what she actually said to him was that MGM didn't even bother to invite her to the New York premiere. Well, everybody else in the cast could say the same thing because there was NO invitation-only premiere in New York. The film had its grand opening at Loew's State on Wednesday May 17, 1950 at 10am to paying customers. It makes NO sense that the studio would not invite their star if they had a formal "premiere," yet the story of the fictional slight persists.