Montréal have had a fairly successful season and beating a playoff caliber team in Austin out in the Western Conference, would make a great message to the rest of the league.
Two reasons we can expand on is beating playoff caliber teams is important and cross conference games are more high profile so more eyes could be on this one than usual.
On the first point, playoff caliber, Austin is a solid squad, built the old fashioned way who are in fourth out West. A win here for MTL would make them legit as it would expand the teams they have wins over and it being at home is extra incentive after a long international break.