Wander didn't fail, they just wanted to change to a serial format (like gravity falls), Disney didn't like that, and they cancel them. As for Star, I love the series, but my guess is that this will be its last season, I guess they will wrap the story in this season. The reason is simple, Star had a strong start, good ratings and reviews, however Disney keep on shuffling the air schedule so now the ratings have been consistently low due scheduling issues, I dont see it surviving another season, the second season was approved due to that strong start, unless they pull a GF and let the writers end the show on their own terms (extremely unlikely)