You are not going to see this issue because you are still using Gmail. If you delete all your Gmail accounts, then you are going to have a hard time uninstalling Gmail Plug-In.
Actually, there are other Gmail issues such as Gmail taking control of your BB contacts and Outlook email which is why I closed out Gmail email account, but was unable to uninstall Gmail Plug-In.
Also, you said that Gmail is your primary account. Does that mean you are not using BIS. If so, no wonder you are not having other problems. My friend is doing the same thing, but I don't think he is using Outlookk.
I like Outlook and BIS, now realize I don't need Gmail and its problems because Gmail causes too many prolems including sync. I don't want to argue Gmail vs BIS and Outlook anymore. I just want to uninstall Gmail so I can stop seeing the unknown contact lists.