Could this be only when you are logged-in to your account in chrome?

I.e.

"if you are logged-in to chrome, it won't delete google cookies because it need it for you to be logged-in to chrome (because of some UX excuse, like user confusion why it's logged-out from chrome).

If you are logged out of chrome, it will delete everything."

If it works this way, I would be willing to give them benefit of doubt, since there is reasonable UX reason to do it this way (given that logged-in to chrome now equals to logged-in to gmail). I personally would expect that deleting cookies will not log me out of chrome.