Newcastle has had no EZY based crew since they closed the 3 aircraft base during Covid, likewise BHX had no crew base before they opened the 3 aircraft base recently. In both cases these airports are a dot on the map (ie not a base) with aircraft and crew based elsewhere and no night stopping crew whatsoever. What's been discussed regarding SOU isn't remotely similar.
They can of course simply operate incoming aircraft on EJU from their EU bases into the UK as is common practice.