So how do we know that it will be announced on the 4th of October? It seems that Google themselves might have revealed it via an ad that was posted in Canada. According to the ad’s listing, it appears to be counting down to a launch date which based on the calculations, would put it for the 4th of October.
Now there’s no way of knowing if this ad was actually purchased by Google so there is a chance that it could be fake. However given the past two Pixel launches were for the 4th of October, it stands to believe that Google might want to keep to those dates. Unfortunately there’s no word on when the phones will actually be available, but in the past we’ve seen Google release it in the same month so there’s a good chance that this could happen again.
In any case we’re still a few months away from knowing anything official so try not to get your hopes up just yet.