As you probably were aware, since early June moderators around the whole SE network have been striking, including at MathOverflow. We appreciate your patience through this time, and there has been a lot of effort in negotiations with the company, as reported in the various update posts here in the past couple of months (1, 2, 3, 4, 5).
There has been a posting announcing the end of the formal call to strike on meta.SE, discussing each point of the demands of the strike, and concluding with:
With this progress being made, and as a result of the various polls held, we consider the goals of the strike to have been achieved and the call for a strike ended.
The "various polls" here refer to those held by various groups that run tools, dedicated moderation chat rooms, develop and run moderation bots, as well as those participating in the Discord discussions around the strike organisation, and a mod-only version of the same. For comparison, the striking math.SE mods are back.
tl;dr — the elected mods have resumed work on MathOverflow.
The backlog of >100 unhandled flags has been whittled down to the usual background steady-state of a just a few. Thanks to all those who kept their eyes open for nonsense while we were striking.