This is not a new thing for McVay. Rams had way too many dropbacks in that game. If you try to ride Stafford's arm through the season you are increasing the chances he'll be beat up for the playoffs. I get the temptation too. It's a thing with all the best OCs, they all get pass happy i.e. greedy with that pass game in certain games or situations.
And generally McVay makes the change. Last season it took a few weeks of subpar offense to get him to dedicate effort to the run and it pulled us out of that midseason slide. 2018 was the same, only instead of adding Michel it was Anderson with the same effect. Rams didn't make a move yet with the RB group as they are healthy for the most part there but they did re-add Brown who could give us a game or two of physical runs before he's dinged up.
You can bet he's going to dial it up vs Dallas. And if not we're going to get manhandled by that front. Our OL is not in that playoff shape they were in some months back when they got it done with no run game. These guys need some snaps where they can fire off and hit that DL in the mouth. And I would run it a lot to the right, behind Jackson/Hav, as I love those two together in the run game.