NAX are also adding a 3rd daily flight to Oslo. That makes, ARN, OSL and CPH all with 3 daily flights. They certainly are getting themselves established before easyJet inevitably move into the region.
As for AB, I think its a given that the operation will all move over in time, like NAX did. I suspect they are just attempting to get suitable slots for their flights, are the ones that are left at STN not peak times, with the exception of like a midday Munster?
Air Asia X, interesting. Could be good for the airline, could be catastrophic. Have to see how that one pans out.
Edit: From the list above, the Luxair and Vietnam mentions are of considerable interest. I imagine that Vietnam are also talking to Heathrow so its only understandably that they are talking to Gatwick. But Luxair seems odd. Would this addition be to complement their LCY flights or instead of?
8R