Die hard Bills fan here.
The Bills aren't so much "all in" with EJ, as they are all in with making the playoffs THIS YEAR, by any means necessary.
With Ralph wilson having passed away, either Pegula or Golisano are going to take over ownership, probably in late August.. they won't clean house right away, as that would doom the season, but the new owner is (obviously) going to evaluate the team from top to bottom over the course of the season.
So one of two things happens following the final whistle of the week 17 game vs. the Patriots. Either the entire coaching staff/front office is gone if the Bills fail to make the playoffs for the 15th year in a row,
or
Everyone in the front office gets a vote of confidence from a new owner, and (likely) free will to spend to the cap--something that was never possible under Wilson.
For any number of reasons, not the least of which is just because we've sucked for so long, I hope option B comes to pass. I think Whaley is an extremely talented GM who has made some absolutely astounding moves that have broken the mold for the Bills since he's taken over. Getting Kiko in the second last year, as well as fleecing Indy for Hughes (who looks like a sure-fire pro bowler this year on an already stacked d-line,) not to mention not overpaying for Byrd (on the PUP for back surgery) and getting a solid young group of wideouts. And probably the greatest coup of all: getting Schwartz in there to coach the D about 3 hours after Pettine left for Cleveland.
With all that being said, I do not think the Bills are all that invested in EJ... if it gets to be week 6 and we're 2-4 with EJ struggling, look for Tuel to take over--by all accounts he's had a great offseason and has looked good so far in training camp. Definitely an interesting story to watch over the preseason though... It's going to be very interesting going into week 1 if the preseason stats shake out like:
EJ 49% accuracy, 2 tds, 3 ints
Tuel: 63% accuracy, 4 tds, 0 ints
If I was a betting man I would say its 50/50 EJ even starts week 1