Wasn't the vendor rotation supposed to stop at September 15th? Hoping for prepatch asap tbh.
They are just simply slapping another week on each time for the sake of letting people plan ahead. It might not actually go as far as the 22nd, but it also might end up going that far. We still don't have a pre-patch release date, however people think we may be getting a Shadowlands release date at Gamescom (starts the 27th) so you can expect the prepatch roughly 1 give or take a week or two prior to the Shadowlands release date.
I don't know why you are writing this article as if the corruption vendor rotation refresh is active in all regions around the world at the same time, I just checked and in Europe it's still the old rotation. If you want to be a bit more accurate perhaps add in the article that it applies to US servers and that other regions the vendor refresh happens some time later?
Pre patch is usually 4 weeks prior to release, except for Legion that was 6.