I wouldn't be surprised if they opened up more seats when it gets closer to game time, especially if the M's game isn't selling well.
Probably because you wouldn't see the Seahawks scheduling a game at the same time as a Mariners game. The Seahawks and Mariners stagger home games. Either by having the games on opposing Sundays, or the Seahawks playing a night game. The good news is the Seahawks don't have to worry about scheduling around Mariners' October games.
The 11-or-fewer rule is in peril tomorrow: if Mexico loses at Costa Rica, then for the first time ever, the fourth-place finisher in the hex will have 11 points (be it Mexico or Panama).