Prevent an update thread starter from sending if no one is tagged

We would sometimes have updates that nobody knows about because the person who sent the update have forgotten to tag somebody in the update so the update is just sitting there. You know, when you send email and you have no one in the TO: field, you get a prompt asking you to fill this up. You can't send an email without the TO field but in Workfront, you can! You don't have to tag if it's not a thread starter - that's understandable but when you start a thread, tagging should be mandatory.