"Just wait until *insert next patch*!"

[Atelier-Bagur]

...how do you know they did this?

Can somebody actually post a credible source for this statement and not just common speculation?

The only people I know for sure that were transferred to the project were some of the Heavensward writing team, which was stated multiple times in interviews and articles.

Other than that it seems more like they scouted talent outside of SE such as getting some of the Capcom guys for fight design.