I don't think it'll be a big deal - airfare is always significantly cheaper on Monday over Sunday so a lot of teams book Monday to begin with, and trying to fly out Sunday is always a gamble anyway. If you're lucky enough to be one of the teams that makes semis/finals, and unlucky enough to have gambled on your departure time, pay the change fee and fly out Monday.
How many teams are there who really have flights they'll make if the day is done at 4 PM, but won't make if the day is done at 8 PM, AND who will make the finals? At most, 12. Realistically, maybe 4.