If the Germany trademark issue was relevant to the moving from gmail.com to google.com/whatever is the case, why were we all allowed to have @gmail.com email addresses?

In Germany they used @googlemail.com addresses.

I know that. I was merely pointing out that if gmail.com was the issue, then having youremail@gmail.com would also be an issue. But since it never has been, the issue in Germany has nothing (based on this simple logic) to do with Google changing the email access from gmail.com to google.com.