Now this is very fascinating. Marilyn Monroe having to come to terms with her aging is obviously something she never faced IOTL, and your proposition for how she does so ITTL is a clever one, however predisposed I might be to actors playing dumb but proving to be shrewd businesspeople as a concept.
MME Productions is a conceit to let Marilyn completely reinvent herself in a sort of film that it seems, to me, very unlikely that anyone would have offered her. (Which I'll get to in the next update or two; I've been neglecting Ronnie again.)
In all seriousness, I suspect that TWR was probably an inspiration to Marilyn, as she did not assume direct control of Desilu until 1962 (after Desi sold her his half of the studio).
From an in-timeline perspective, I'm sure Lucy was something of an influence. However, I don't want to get too far into what happens with Lucy and Desilu because I'd just be riffing off of your TL, but with much less research. (Seriously, this is all just wikipedia and IMDB.)
That said, a certain program from Desilu will be affected in the next few years.