I kind of see this playing out like the Manning thing last year. They will start Dak until he has a bad half, throwing a couple picks or whatever, then bring in Romo to save the day and he will start for the remainder of the season.
They can't keep Prescott on such a short leash for several reasons:
A) The Philly game proved that he's the type of player that can pick himself up off the mat and still somehow find a way to win.
B) He's not Brock Osweiller.
C) Related to B, even with that ridiculous defense, the Broncos still only managed a 5-3 record under Osweiller.
D) Prior to Manning's injury, the Broncos were 8-0 - the Cowboys are 0-0 under Romo this year.
E) Manning only missed half of the season. Romo hasn't played a full game in well over a year.
F) They would have a mutiny on their hands if they were to make such a knee-jerk move.
I'm sure I could find some more and go on, but I'm sure you get the picture. The fact of the matter is that Prescott will have to go on a very shittastic run before they hand the keys over to Romo, which, considering the remaining schedule, is a possibility. But they can't make any rash decisions, which was kind of the point of my kicking the can down the road comment.