They've apparently switched all their works over to the new 'Everytown' name and they've put up a scrolling list of 'Coalition Members' which was taken down several months ago. No links or names like they used to have, only the cities, but it's not hard to Google the cities to find out who's in charge. Here's the screencapped IL list:
They've also changed their wording to "a bipartisan group of more than 1,000 current and former mayors" since so many of their 'members' have lost elections. Much nicer to show that made up number than the decreasing one.