I do not think so. Managing data collection for models, especially historical cars, has to be time consuming. Once they decide to include a certain model, they have to search for a currently available car, negotiate with the owners, and agree to a visit, travel to the place to take reference photos, videos and audio recordings and then process and organize all this information that will serve as basis for 3D modeling and simulation.
I think Polyphony should already have all the necessary data to recreate with current standards models that have appeared in other games, perhaps not for GT4 and earlier, but for GT5 and later.