Maybe, I'm over-thinking it, but since this is a story-line having to do with the industry and instruments that give us the show, I think the details would be considered. And I think she quit the superficial career to do something more substantive. I guess we'll see, but I interpreted it much differently. That's obviously by design. I saw it as both a concession and recognition of her gravitas in front of a camera. Like wow, maybe she can do this and just needs some exposure. If Don hadn't met Roger in that bar, who knows if he'd be where he is and I think he hasn't lost sight of that. And he wants her more than she wants him. That has been established. She would be more comfortable splitting up than he would. She would not put up with being treated like a possession.
I don't see this at all. IMO even though the show is obviously a product of show business the perspective is that acting is one step up from modeling. Remember we're talking about Don's perspective, not the audience.Don pushed his way in after meeting Roger in the bar. Megan let Don push her way in for her after meeting Don in the office. Huge difference, or at least I think it's probably a huge difference in Don's eyes.
I agree she doesn't seem like (or isn't written as) a woman who would tolerate being treated like a possession, but I'm just talking about Don's attitude towards her. Clearly we're supposed to think there was a significant change in that in the season finale.