The Unihorn's word for "home" changes throughout the episode depending on who is saying it. The Unihorns say "oop" while the main characters say "boop".
When Wubbzy and his friends find the Unihorn herd, the Unihorns are all saying "oop!" which is revealed to be their word for home. There's no reason they should be saying that because they all were home.