Might have something to do with the winds perhaps. Fuel tends to run a little low whilst holding and an "emergency" is normally required to be declared once reserves fall below a certain level if priority to land is required before other aircraft. Chances are that many diversions will have gone out of limits, closed due to debris on the runway or because they are full of diverted aircraft. This event probably no big drama at all Although with gusts to 60, the approach might have been a little sporting.
Manchester is currently closed due to debris on the runway and is not expected to open until 17.00. Hence people are diverting to wherever is open, in limits and can accept them. A "full" airport will always open up again to an aircraft declaring an emergency. Liverpool only taking one more diversion at 15.00.