"couldnt switch"...now come on- thats not strictly true. They could easily use an A330, and double daily to keep capacity if necessary.
I note Emirates are also stating that the yields wouldnt necessarily be any better at EDI and there would obviously be relocation costs associated with it. It is my feeling that they are unlikely to switch, and a new operator at GLA is likely to offer cheaper landing fees IMO.
Another middle eastern operator perhaps ex EDI, but there is certainly nothing currently in the pipeline.