> None of your comments have actually provided evidence for this assertion

It's not an assertion. It's simple reading comprehension. How else can you interpret this?

"Over the last few months, we have continued with the Manifest V2 phase-out. Currently the chrome://extensions page displays a warning banner for all users of Manifest V2 extensions. Additionally, we have started disabling Manifest V2 extensions on pre-stable channels. [paragraph break] We will now [emphasis mine] begin disabling installed extensions still using Manifest V2 in Chrome stable."

> So when between June 3 and October 9 did Google start actually disabling MV2 extensions, and where was it publicized prior to their October 9 update?

I don't know if it was publicized, until now.

After all, when did they publicize that there would be a warning in Chrome stable? But there is a warning in Chrome stable. That started happening some time before this announcement.

Four months is a long gap between announcements.