Even though the manga ended the anime is still churning out filler content prolonging the conclusion of the main storyline.
But I think I know what studio Pierriot has in mind. With the Boruto manga coming out there's going to be even more manga content to adapt into anime, so perhaps the plan is when Shippuden ends they're going to go straight into the next series starring the new generation of Boruto. If the manga isn't finished by then it's going to be easy to plan out the anime and if it isn't successful they won't want to be stuck waiting for the manga to end while they need to create more fillers. So they're putting fillers in now so by the time Shippuden ends they'll have the entire Boruto manga to adapt into a sequel series.
But I think I know what studio Pierriot has in mind. With the Boruto manga coming out there's going to be even more manga content to adapt into anime, so perhaps the plan is when Shippuden ends they're going to go straight into the next series starring the new generation of Boruto. If the manga isn't finished by then it's going to be easy to plan out the anime and if it isn't successful they won't want to be stuck waiting for the manga to end while they need to create more fillers. So they're putting fillers in now so by the time Shippuden ends they'll have the entire Boruto manga to adapt into a sequel series.
