Looking at the timing, I think it would be unwise of the producers to try to squeeze Almost Famous in before the Tony cutoff. Inheritance closes March 15th, and the Tony cutoff is April 23rd. So in order to get 4 weeks of previews, they'd need to load out Inheritance and load in Almost Famous within a week. I'm not sure if that's possible. But even if it is, and even if Almost Famous is logistically ready to do that (i.e, they've adjusted their set design to the dimensions of the theatre, everyone from the try-out cast is available and ready to hit the ground running, etc.) I still don't think it would be smart for them to try to rush this in, and potentially deny themselves the necessary development time.