Precisely. They usually used this as a hype/discussion kicker in the last weeks before the release of the book, and once the hype about the prologue had petered out. The only thing making sense for releasing chapter 1 in the same week as the prologue is that they're moved up the release date and are now rushing their in-house marketing devices like this.

They have apparently one or two more chapters to release for promo, one will be audio only (promo for the audiobook).

That sounds like a late october/early november release to me.

I may be completely wrong but ever since they announced october 2 for the prologue when the book is set for January, I found it fishy.

Mind you, Brandon recently still talked about doing the tour in February because he's expecting his baby - IRRC - around the release date. But Brandon wouldn't necessarily be in the loop if they're moving up the release date, and the dates of the tour wouldn't necessarily change anyway.