The studio's founder, Kazunori Yamauchi, published a personal appeal to candidates, recalling the 25-year history of the series and thanking players for their support, but adding that the studio's achievements are still not enough.
Yamauchi is looking for people with a thirst for creativity to "create the future through art and technology." Presumably, the potential Gran Turismo 8 is being developed with an eye on PlayStation 6. This approach will allow the studio to fully utilize the capabilities of the new platform without limitations, which has always distinguished the series.
Given the complexities of developing modern projects, it is not worth waiting for the release in the near future.