I'm not sure if
@AlexWilmot is questioning it as confirmation that the cars will appear as opposed to the validity that it's datamined from GT7.
I agree with you regarding the source, there's no reason to doubt it's legit and the work that
@Nenkai and others are doing with datamining Gran Turismo titles and modding them is absolutely fantastic. Though I still need to buy myself a new PS3 so I can get modding GT6 myself. But back to the list, the fact it's legiticamtely from GT7's files doesn't mean these cars will be appearing in GT7, it could just as well be legacy data.