This reminds me of a situation a few years back, I think it was Miami & the Pats. NE scored as time ran out, teams left the field and the refs had to go into the lockers to get them back which took some time. Miami was dejected and uniforms had been removed so they declined to put a team out on the field. With no opposition Belichick in true Belicheck fashion had the QB walk into the end zone for 2. Thing is the 2 effected the betting outcome. I don’t recall details but that’s the kind of thing that will drive you nuts if you lose like that.
That was regular season but I fail to see how post season would differ. Sudden death states any score ends the game, an extra point is an extension of the game so it doesn’t happen. Regulation isn’t sudden death and the extra point is part of the td regardless of it extending the game. Perhaps the playoffs have some kind of exception but I don't see why it would.