GT7 with 1000 Cars at Launch is NOT Unrealistic !
Provided they have outsourced a large number of companies and firms to model a huge variety of cars, as well as developed new technologies and methods to produce cars at a consistent quality at a quicker rate of time, I don’t see why that’s unrealistic. But it is too ambitious though, especially given the weird times that this year has brought.
Nowadays the PS2-quality cars in GT4 to GT6 would be almost improbable to add because their graphics and modeling look like they come straight out of Automodellista, unless fully rebuilt as a PS5-spec “hyper-premium” car.
But to be cautious, I expect GT7 to have around 650 to 750 cars at launch, thereabouts. Then with updates throughout its lifespan we can see around 800 to 900 cars. There are currently 336 cars in GT Sport, but had Polyphony went all out on creating content for GT Sport than focus on GT7, the number of cars in GT Sport likely would have been much larger.
Provided GT7’s development started some time after GT Sport’s release, that was a lot of time to add quite a decent number of cars. Whatever was added to GT Sport may have been the start, but Polyphony might have held a number of cars back (which may explain that the volume of updates towards 2019 and this year alone have gradually gotten smaller).
The fact that they’ve begun to outsource can also be a contributing factor. We only know of two so far (ModelingCafe and an Indian computer modeling firm), but there might have been more that only Polyphony knows of.
We don’t know the exact number of Polyphony’s modeling staff, but say if they’ve worked on 100 cars in 2018 alone, then they might be around 50 people, as it would take six months for one car to be complete. But it was once said somewhere that fictional race cars, based on real ones, could take up to a year to create. That, along with their outsourcing efforts could mean around a minimum of 650 to a maximum of around 750 cars at launch is possible.