This project seems more "event" based than season-based.
That's probably just hedging their bets -- they're starting out planning for just one season in case it doesn't go beyond that, but if the ratings are good and they can make more money by doing a second season, then they certainly will do a second season. Although if some of the shows do better than others, we may not get renewals for all four. Maybe one would be cancelled and another would take its place in the next season.