But all three logos were designed and introduced at the same time as their corresponding favicon. Your claim was that the favicon was just a copy of an existing part of the logo.

Your claim was that a favicon could be a different font than in the logo. But these examples are all a part of the logos. Google would have needed to rebrand their logo to do the same.

The claim was, "Using a different font [on your favicon than the one you use in your wordmark] would make absolutely no sense."

I believe I have successfully refuted that claim.