I have to think McDaniels sees the deteriorating offensive talent on the Pats roster and sees a chance that he could lose some luster. The Pats offense put up some nice stats this year but it’s hardly the type of performance top OC wants at the top of his resume (and recent experience always gets the most attention)
Unless you’re of the belief that Gronk is coming back next year AND will improve for his mediocre 2018 self AND will stay healthy, then it’s fair to assume the Pats passing game will continue to be inconsistent and no longer elite. They simply don’t have internal options or cap space to bring in quality vets. Rookie WR, if they can draft one successfully, tend to take time to earn playing time. It’s going to be a mess at the TE/WR position for the rest of the Brady window.
Easy to think McDaniels tries to get out before the offense declines further. His 2014-2017 was the pinnacle of his career (2007 was a decade ago and many chalk it up to once in a career talent on offense). Makes sense to get out before the patchwork offense drags down the perception of his performance.