They made a bunch of changes at ES around the new year, explicitly directed at tr1 and eliminating the blatant Cowboys-baiting posts he excelled at.
I didn't follow much after the new rules went into effect, but my hunch is that it probably didn't go over well with tr1 and probably negatively influenced his relationship with that board.
Around the time he stopped posting over there, one of the last posts he created was one asking "where's Bubba?" before his fate was known. In that post, tr1 took a veiled shot at the new rules over there, and was reprimanded by the mods for doing so.
I don't know if he was banned or not, but my hunch is that the combination of the new rules and perhaps even bubba's death led him to leaving the board, at least for the time being.
It's a shame. His posts were entertaining and his (and bubba's) extreme homer posts were fun to argue against.