My likely Gr.2 picks:
Aston Martin Vantage DTM
Bentley Speed 8 '03
BMW M4 DTM
Honda Civic Type R GT500 '24
Mercedes-AMG C-Class DTM
Nissan Z GT500 '24
Toyota GR Supra GT500 '24
I picked the Bentley because it raced in LMGTP, just as the Toyota GT-One did. (That said, I think cars from the LMP, LMP900, or LMP1 classes will likely go into Gr.1, such as the BMW V12 LMR.) Additionally, I think it'd be perfect to specifically pick the 2024 GT500 trio, since that'd mark eight years between them and the 2016 trio, which in turn is eight years younger than the 2008 trio. Meanwhile, I don't see the FR version of the NSX GT500 nor the HSV-010 being similarly as necessary. However, I definitely could see a variety of GT300 cars going into a combination of Gr.3 and Gr.4, with the Lexus LC500h GT300 '21 being an excellent candidate for a newer Gr.3 car for Lexus.
EDIT: And just for giggles, I wonder if the Lexus LFA that raced in the N24 could appear as an additional Gr.4 entry?