Right, but they should be in the game already. The link you posted even shows that they're finished. Why can't Kaz even give a bit of info regarding future content, when we've already seen it? It's not like it's a secret they've just withheld content instead of adding it on release.
Cars and tracks are surely finished by now. There's not much added over GT Sport, what else were they doing in that time?
Race events take barely any time to set up, and we know there's more finished, they should be in.