I believe that's how LinkedIn works, but it's also the case even when attempting to permanently delete your account. I finally managed to successfully delete my LinkedIn account around 8 months ago, but then recently I accidentally followed a link to a LinkedIn page on my work machine, and apparently there was still a cookie around, so LinkedIn was kind enough to reactivate my account without warning. And oh how the spam did flow.

To be extra careful, I think you need to unsubscribe from all email, deactivate your account, delete all LinkedIn cookies from all your machines, and you might as well kill linkedin.com in your hosts files.

Does the settings page itself show all the options there set to "No Email"?

If any item is not showing "No Email", then there might be something wrong with the script/bookmarklet for you. If all the items show "No Email", then LinkedIn does not provide options to unsubscribe some emails.