Apple avoids shipping new hardware in November/December because they want their holiday lineup to be set by then. There is zero chance of January, don't even know why that's a poll option.
In fact, Apple deliberated bailed out of the now-defunct Macworld Expo because they did not want to be forced to come up with new announcements in early January. That worked again the retail buying cycle and was problematic with employees taking time off (Hannukah, Christmas, New Year, etc.).
Besides, Apple said THIS YEAR at WWDC.
The most realistic Apple Silicon Mac release window is the latter half of October.
Let's also remember that Apple did not refer to the new devices as ARM Macs. They specifically and repeatedly called them Apple Silicon. During the WWDC keynote, Apple made a great effort in not highlighting the Arm architecture. They were also very consciously vague about the GPU architecture during the keynote instead rather blandly using the "Apple Silicon" phrase to describe the entirety of the hardware.
I know a lot of people are fixated on the fact that the new Macs will have Arm-based CPUs but it's really all the other proprietary functions that Apple has developed in other custom silicon that will make Apple Silicon Macs different than the competition.