The Japanese developer has published a kind of teaser on his Twitter account with a picture of a blue sky and clouds on the perfect summer day. Gust has several franchises that fit this image so it is a matter of waiting.
The most popular saga in recent years has been Atelier, the new story with Ryza has brought many successes to Gust that already declared Siliconera
Gust prepare another RPG
That would be the first bet for the mere fact that it is the most profitable for Gust. Then we would have the Blue Reflection saga which was moderately successful on consoles and PC. In fact, Gust has already announced a new installment for PS4, Switch and PC still without a date and another delivery for mobiles that does not have a date either.
Blue Reflection also premiered an anime called Blue Reflection Ray just three months ago, making it truly the most recent franchise to receive an audiovisual product. That is why we would not rule out that the teaser refers to any of the games mentioned in the saga.
Finally, we would have Nights of Azure or Ar Tonelico, which are less known and have been less successful. However, they are still Gust games so they could well be the ones that get renewed on July 6.