Pocket Monsters XY Sound Director Mima Masafumi (三間雅文) posted the following Tweet on his Twitter account on September 5th, 2014. He indicates that a new season of the The Rocket Gang Secret Empire (ロケット団ひみつ帝国) is in the preliminary development stages. He hopes to revive the series and its now being discussed with the Rocket Gang members Musashi, Kojiro and Nyarth who are played by Megumi Hayashibara (林原めぐみ), Shinichiro Miki (三木眞一郎) and Inuko Inuyama (犬山イヌコ). There are no official details though as the next series is still in development and has yet to be proposed.

そして、全世界のロケット団団員の皆さん！ついに出来上がった『ロケット団ひみつ帝國・復活の図』の企画書だ！再び、団員達の力を結集する時が来た！まだ、企画書段階だが団員達の知恵と勇気さえあれば、必ずや復活するだろう！ pic.twitter.com/4lk6mfcsvc

— 三間 雅文 (@Sunma47) September 5, 2014

Source: https://twitter.com/Sunma47/status/507924948426293248