When you click on 'Pause actions of all alerts' in the All Active Alerts window:
you get a notification in the Alerts window to that effect:
However, if you navigate away from that page, spill your coffe, run to the washroom to get towels, run into your CIO, then get cought up in discussion with your network admins, all before sitting back down, then finding out it is time to go home...you may not realize until the next morning--since you got no alert calls all night long!-- that it was left in a muted state.
instead, I recommend implementing a banner that shows up on all pages that alerts have been muted. Then, anyone who uses the UI will notice, even if admins are the only ones who can turn alerts back on again.
workaround for now: we run the 'Current Muted Alerts (v5)' 2x/day to help alleviate this issue. However, having greater visibility is preferred.