The United States normally plays matches and easily accessible channels. Their TV rights are split between ESPN and FOX, so ending up on Fox Sports 1 or ESPN2 is considered "tough to find" for them. But when it comes to World Cup qualifying, things aren't so easy and the Americans could end up playing vital matches on a channel you don't get at home. How does that happen?
For World Cup qualifying, the home team controls the TV rights. That's not just in their home country either, it's worldwide. So when the U.S. plays in Mexico, Trinidad and Tobago, Guatemala or anywhere else in qualifying, that country gets to sell off the TV rights in the U.S. and everywhere else. U.S. Soccer's TV contracts with ESPN and FOX don't apply and there's nothing they can do about ensuring the match is on a widely distributed channel.
American fans will remember that beIN Sports bought the English-language rights in the U.S. to all Costa Rica, Honduras, Panama and Jamaica matches in the final round of 2014 World Cup qualifying, so every match there was broadcast on their network. That was problematic for a lot of fans and forced them to find a bar or friend's house to watch the qualifiers because they didn't get beIN Sports. In the past, pay-per-view networks have bought road qualifiers, making it impossible to watch the U.S. unless you were willing to pony up for it.
You can expect something similar to happen this World Cup cycle. beIN Sports already bought the rights to the U.S.' first road World Cup qualifier, so the Americans' semifinal round match against Trinidad and Tobago will be on there. There's no telling where the rest of the matches will go either.
All we know is that every home World Cup qualifier will be on an ESPN or FOX network and that a qualifier at Mexico would be on ESPN, per their deal with Mexico. Everything else is still to be determined. The good news is that Univision or Telemundo usually get the Spanish-language rights, so that should be an option almost every time, but only if you know Spanish or are okay not understanding the announcers.
The TV situation for road World Cup qualifiers sucks. Every fan knows it and U.S. Soccer knows it too. If they could sell the rights to ESPN or FOX (even NBC or another easily accessible network), they would, and they have worked with those networks to try to buy up road qualifiers before, but it's not always possible. So you will have to watch some matches on beIN Sports or some other network, maybe even pay-per-view. That's just how this goes.