You can't add a turbo to the 964 Carrera though. Besides, the Turbo is a completely different beast in terms of performance and styling, and it'll almost certainly have some unique customisation options on offer.
Even besides the fact it'll likely drive amazingly, it's absolutely a worthy addition to the game's roster.
Huh, interesting. Reminds me of how we have two road-going 992-era 911s, but they couldn't be more different: the Turbo S '20 is AWD and turbocharged, whereas the GT3 RS '22 is RR and NA. That's before we mention the race-spec GT3 R '22, as well...
At any rate, I don't think we'll get a new Bonus Menu, but I do anticipate a new Seasonal Menu featuring all three new cars. As for a potential Extra Menu? If we get one, it very well could still feature one of the new cars, just like the Hyundai Elantra N TC '24 did in its respective update. Like another poster mentioned, it could focus on the Porsche 911 Turbo, with the 930, 964, and the 992. We've had one on mid-engined Porsche models, the 911 Carrera RS models, and Porsche supercars. There's also the Porsche 911 menu in the main campaign, which does indeed feature the 930, but the other two models are of the Carrera RS name, though both of said Carrera RS models were featured a second time in the aforementioned 911 Carrera RS Extra Menu.
Alternatively, maybe we could get an Extra Menu featuring relatively eccentric Renault models, featuring the Twingo, the Kangoo, and the Avantime.
EDIT: I do still have my fingers crossed for at least one more mission set but I'd also be very surprised if we got one this update.
EDIT2: I don't know if I'd rule out a new Circuit Experience, either. Certainly seems to be some short layouts we could see, between Suzuka, Autopolis, Fuji, Brands Hatch, Watkins Glen, Lake Louise, and Red Bull Ring. Plus other layouts like Sardegna B and C, and St. Croix B, let alone various reversed layouts that I likely forgot.