Sorry but where does he say there will be no career or campaign mode?
The evidence is laid out in the first post with facts, it's up to you how you want to interpret it.
To me it's quite clear, 'Sport Mode' is the main, leading mode of this game and it's entirely online. Some people are hoping the classic SP career is going to pop up somewhere but I just do not see where, or how, given their focus on the Sport mode so far and his comments that this is the rebirth of the series, essentially.
As the link @Tassie_tiger provides it clearly states that 'Campaign Mode' is the offline content of the game and they've already detailed what that entails, as per the OP.
I just do not see in the coming months Kaz saying "Surprise" and up pops something like we've seen in 1-6, with basic cars, custom parts, building your garage up and taking on a single player career. Nothing they've said or shown so far suggests that is something GT Sport is going to be about.