For Forza Motorsport 8 there have been no further impressions since the first revelation trailer.
It was then announced that Turn 10 Studios would like to implement the development as close as possible with the fan base and thus implement a very early test phase with some players.

From this alpha test version of Forza Motorsport 8, which is to date from 2021, screenshots have now been gelaked that you can look at here:

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Forza Motorsport 8 is now in the beta test phase, according to Jez Corden and more and more players and “influencers” are allowed to play it, or have already played it:
According to other rumors, the racing game could appear in October.