Well, that was quick 
Two days after the last update we have another batch of cars to add to the list, coming from today’s Forza Monthly stream with career mode gameplay.
8 new cars on the official list:
- 1990 Alpine GTA Le Mans
- 2013 Audi R8 Coupé V10 plus 5.2 FSI quattro
- 2020 Automobili Pininfarina Battista — #NewToForza
- 1999 BMW #15 BMW Motorsport V12 LMR
- 2014 Ford #17 AMD Tuning Focus ST BTCC — #NewToForza
- 2014 Lexus IS 350 F Sport — last seen in FM6
- 2023 Lotus Emira — #NewToForza
- 1999 Toyota #3 Toyota Motorsports GT-ONE TS020 — last seen in FM6
20 additional cars spotted in the gameplay:
- 2005 BMW M3 — poster
- 2021 BMW M4 Competition Coupe — poster
- 2019 BMW Z4 Roadster — gameplay
- 2016 Chevrolet Camaro Super Sport — poster
- 2015 Chevrolet Corvette Z06 — Builder’s Cup keyart
- 1992 Ferrari 512 TR — poster
- 2014 Ferrari California T — poster
- 1993 Ford SVT Cobra R — poster
- 2011 Lamborghini Gallardo LP 570-4 Superleggera — Builder’s Cup keyart
- 2010 Lexus LFA — poster
- 2011 Lotus Evora S — gameplay
- 2012 Mercedes-Benz SLK 55 AMG — gameplay
- 1969 Nissan Fairlady Z 432 — poster
- 1992 Nissan Silvia Club K’s — poster
- 1995 Porsche 911 GT2 — poster
- 2018 Porsche 718 Cayman GTS — gameplay
- 1998 Toyota Supra RZ — poster
- 2020 Toyota GR Supra — gameplay
- 1983 Volkswagen Golf GTI — poster
- 2021 Volkswagen Golf R — poster
But there are also 8 cars that were earlier on official lists but now are missing:
- 2020 Acura #6 ARX-05 DPi — #NewToForza
- 2020 Formula Drift #151 Toyota GR Supra
- 2018 Lamborghini #63 Squadra Corse Huracán Super Trofeo Evo — #NewToForza
- 2010 Mazda #16 Mazda Racing B09/86
- 2019 McLaren Senna GTR — #NewToForza
- 2018 Mercedes-AMG GT3 — #NewToForza
- 1988 Mitsubishi Starion ESI-R
- 2016 NIO EP9
And one final note: the 2018 Audi #44 R8 LMS GT3 is now back on the list of cars coming to the game on launch (it was removed a couple of months ago).
EDIT 14/06: It turns out that there are 8 missing cars, not 7. The 2020 Acura #6 ARX-05 DPi is gone as well.
EDIT 17/06: I’ve added the 2010 Lexus LFA to spotted cars.