Lol, amazing the leaps folks will make, on the other hand one could look at McVay's history to see that every OC that worked for him wanted to leave after one season.
LaFleur took a lateral move, O'Connell was blocked from taking a lateral move and now Coen is headed back to where he built his own success.
Alas, people can create any theory they like.
For me I would find it incredibly hard to believe that McVay would be so incompetent that he would force out a coach that doesnt call plays, runs McVays own system, and had left a job he revered, all because the offense was terrible due to an unprecedented injury run that exposed some poor personnel decisions. And this of course right after the same departing coach has been applauded for his work with Mayfield.