Chris Esaki mentioned that topic on the stream, commenting on players’ accusations that this layout is “fake”. He tried to understand why anyone is saying this, but didn’t think that’s because they just placed historical part of track in modern scenery 
I’d love to see truly historical tracks in Forza too (considering how many historical cars there are), but I’m afraid it’s not going to happen. It’d require them to create lots of new assets for environment, and if they didn’t make them already for “historical” Laguna Seca (which I’m still disappointed with), then probably it’ll never happen… unless, perhaps, there is at least 1000 votes on track such as this one: