If the ATCOs have lost flight data, that will likely include their electronic strips, which will include all the aircraft on the airfield that have started and are moving, recovering that situation will mean a complete stop on new movements.
Recovery from that will take time, reversion to hand written strips is only possible if you have the data to hand AND there is provision for it.
Data transfer at large airfields, both in and out is electronic, you cannot magic a EGBB inbound coordinator out of the air at Swanwick or Prestwick centres, there are just not the staff or procedures to do it.
If EGBB called a stop, they did so for very good reasons.