Supposedly its even worse in ALTA. There is a rumor going around that in net news (the free ALTA magazine they send out quarterly) there was a rules question about a captain that said that they would be defaulting a line the day before the match but then showed up and had a full lineup. ALTA said that a default is not official until the lineups are exchanged.
To me this is a brutally bad precedent. In ALTA the all time dirty trick would now be that a team could say that they had an out of town wedding and that they could only field one line for a 9am match. So if the opposing team sent just one line to the match but the dirty team instead had two lines. The innocent team would end up defaulting lines 2 though 5 unless they could get 2 more people there by 9:20.
I really thought that this was an urban legend that even when a team says in writing that they are defaulting that they would be allowed to show up at the match with a full lineup but I guess not.