Every 7 or 10 years, when the economy is doing reasonably well, talk arises of setting up a new business class only airline. I definitely recall this happening ever since at least the 1990s. Inevitably when recession hit, these airlines felt plenty of pain.
Whether the idea's time has truly come is difficult to judge. I suspect BA running LCY-JFK have a much easier time than a very small airline will at LTN, LGW or STN.
The only thing I do know is that we are possibly now seeing investors being somewhat more (over ? )lenient with start up funds and the airline industry might be entering a phase of overcapacity which is viable only when the economy is healthy.