"Restart the Tor Browser to apply updates" notification disappears with New Identity, maybe it shouldn't?
Imagine there's a new wild 0day of TB going on and you release an update hours after, but some user isn't attentive enough and doesn't notice the notification to update and eventually clicks on New Identity and ends up without the update taking effect for quiet some time...
(Another alternative could be a forced update that forces a restart, but people won't be happy with that)