In reading the many comments regarding the respective authority and responsibilities of ATC and a captain and recognizing the concurrency of requirements of traffic flow and managing an emergency due either to fuel or weather limitations, it may be worth re-reading the NTSB Report on Eastern Airlines 66, available
here.
In the report, there is support, if that's what one wishes to call it, for both arguments - captain's final authority when the ship is threatened and ATC's responsibility to maintain traffic flow, knowing that a runway change may solve one crew's problem but will create dozens more who may be close to the same situation.
The key of course is, how severe was the emergency and as someone has already pointed out, that will become apparent in the days to come. Both weather limitations, (crosswind) and fuel were the reasons given and it is reasonable to expect that either or both will be examined as the basis for the request, along with the airline's fuel policy and the captain's weather briefing at departure, etc, etc, etc.
It is abundantly clear to all professionals here that declaring an emergency to jump the queue is unacceptable so the burden of proof, after the request is granted and the airplane is on the ground, remains with the captain - this has already been stated many times: the captain has the authority to do what he-she wants but must be able to answer for such decisions. So too, must ATC, when denying or delaying the necessary assistance to a flight declaring an emergency. It is not ATC's right or requirement to outguess a flight crew.
There are parts of the NTSB Report on Eastern 66 which are relevant to this issue, again for both views.
We were four back behind Eastern 66 when he went in and along with others went around and held at Southgate before getting a clearance to divert. As we turned south at Hancock for the Empire intersection, (now the Ellis intersection if I recall), we began to see how huge the thunderstorm was; it was the largest I had ever seen up to that point, with huge contouring. The ride in the descent was through heavy rain and turbulence, the noise on the windshield over which we had to shout to be heard by one another. Our approach to 22L had the same conditions yet even after several aircraft went around and some said a change of runways was required, the approaches did not change.
I fully realize the many differences between that accident/circumstances and this incident and am not comparing the two with a view to justifying either of the arguments being presented here. But there are sufficient similarities to be instructive,
for both sides.
PJ2