I think your post is a strong read on the mood of the fanbase, nothing too shocking, but I am not ready to assume Sark is burned out or halfway out the door. He has always worn losses on his sleeve, and he still recruits and coaches like someone fully committed.
Where I disagree a little is on the idea that asking Sark to give up play calling somehow negates the reason he was hired. Yes, he has a strong offensive pedigree. So did Ryan Day. So did Nick Saban and Kirby Smart on the defensive side. They eventually delegated some of their identity work because the program reached a stage where doing everything was no longer efficient.
Sark was hired to resurrect and redirect the program, rebuild the roster, and prepare Texas for the SEC. He accomplished that. Now we are in Phase Two. The expectation shifts from building the foundation to winning at a high level and sustaining it. If delegating play calling helps us make that jump, then that is not a betrayal of his identity. It is a natural evolution that elite coaches make when the demands of the job change.
I still agree with your bigger point. A full reset would be the worst possible outcome. The best path forward is likely for Sark to stay, adapt his approach, evaluate his staff honestly, and adjust the offense to the weekly reality of SEC competition.
I don't think yesterday was any special day or inflection point. This season is what it is. How he responds during this offseason will tell us exactly what the next few years of Texas football will look like.