Conversation so far:
when does the next episode of naruto shippuden come out in english
The English air date of Naruto: Shippuden Episode 339 entitled I will Love You Always is to be announced (TBA).
what was the last naruto shippuden episode to air
The English air date of Naruto: Shippuden Episode 338 entitled 'Izanagi and Izanami' was March 25, 2016.
why did the english airing of the naruto shippuden stop at episode 338
The English dub of the season 15 aired on Neon Alley until episode 338 on March 25, 2016, when Neon Alley was beginning its shutdown and Naruto: Shippuden removed rotation.

Question: what caused the shut down
Self-contained rewrite: what caused the shut down of Neon Alley