I think your contrarian view is biased and misleading.
The HTTP request for favicon of each email’s domain, which you hypothesized, might be the issue that Google was thinking of. However, your hypothesis has never been clearly stated during rounds of emails between the developer and Google.
Wouldn’t it be helpful to clarify an issue in reply to the developer, rather than having someone post “a contrarian view” afterwards?
The HTTP request for favicon of each email’s domain, which you hypothesized, might be the issue that Google was thinking of. However, your hypothesis has never been clearly stated during rounds of emails between the developer and Google.
Wouldn’t it be helpful to clarify an issue in reply to the developer, rather than having someone post “a contrarian view” afterwards?