We'll probably never know the exact circumstances of Tomlin stepping down, as that was always going to be the public face put on it no matter what.
Remember, this is the same organization that Bruce Arians and Dick Lebeau "retired' from.
It's possible Rooney told Tomlin he wasn't exercising the 2027 option, knowing Tomlin would not go into 2026 without a commitment beyond it. In that sense, it would have basically been a firing.
I thought it was interesting when Art2 was asked about the 2027 option after Tomlin resigned.
He basically dodged the question by saying he won't disclose contractual issues and had every intention of Tomlin being the coach in 2026.