Maybe.
The one thing tht puzzles me is why it took so long to install Roenicke if tha wa the plan. I'm talking about the time it took just to make him interim manager. If they were going forward with 2020, as you say, they certainly took a long time just to come around to promoting the bench coach to temporary replacement.
I can't say one way or the other on Cora, but I don't think his return is the slam dunk you are predicting. In fact, after this year, Cora is free to talk to any team about a managerial role. Had the Sox not fired him, they could have prevented that possibility...