They probably went to out of base greenslips or whiteslips. If they pulled them for reroutes that would be illegal since the trips were known about more than 14 hours out. If I were you, I would check into it. I do know a lot of illegal reroutes go out especially when they are short in that category, but most of the time no one knows they are illegally rerouted. I think ALPA needs to step up audits in this area.