They haven't. The May showing was deliberately underwhelming to manage expectations. No wonder Kaz was in such a good mood. Trolling everybody the whole time.
Now that it's confirmed the game will be pretty like every other Gran Turismo hopefully the spotlight can be put back on the important stuff.
They really fucked up the reveal of this game, and it did real damage to the franchise. First impressions last.
This is like SE revealing PC to PS4 FF7 port then revealing FF7R a few months later.