Multiple simultaneous fuel emergencies declared?
Sounds to me like a systemic aspect exists here.
Company policy (aka local training department) browbeating crew to fly with minimum fuel and some delay occurring (this pressure has been a persistent problem in several companies as we well know) - suddenly several of that company's aircraft are trapped in the hold and crews begin sweating. All know what they ought to do but human nature being what it is hold off on the hope of a reprieve in another three or four minutes to save the interview and all the paperwork - and possible pointed fingers...finally someone has the sense to do what everyone is thinking and the dam bursts; there is a relieved cascade of MAYDAYS from crews who are thinking, well, at least it isn't just us...
Just surmise you understand...