Only past seasons of Disney TV shows are available on Disney+, current shows airing on cable can be streamed through DisneyNow if you have a valid cable subscription.
there's also some weird rule Disney has where they won't make more than 65 episodes for a Disney channel show or something, I dunno. Ducktales ends at 65 episodes of season 3
The 65th Episode Rule was a controversial rule that applied to all Disney television shows, particularly during the late 1990s and early 2000s stating that no show can go beyond 65 episodes (2 or 3 seasons). This rule angered many Disney Channel fans, due to the fact that many shows had been...