The first photo of Tom Riley as Lt Willis Keith in The Caine Mutiny Court-Martial has been shared by La Biennale di Venezia on social media. The premiere / press screening of the film takes place (out of competition) tomorrow evening 2nd September 2023, and main premiere it seems on 3rd September.
Tom Riley's name has been added to the cast list on IMDb for feature film The Caine Mutiny Court-Martial. Tom's character is listed as Lieutenant Willis Keith. I haven't been able to find an official announcement anywhere, but it seems that the film started filming in January 2023, and is now in post-production.