Well, if true then that is fantastic news. It also seems like a very sensible route choice- a base at one end, a well-known route from SOU and one which has/will see capacity reductions from Volotea and Flybe when the 195s go.
4 per week also leaves Flybe a niche in which to operate if they choose to. I suspect on this route EZY will drive their own demand by putting SOU on the radar of people who may not have considered it before, as well as stopping some leakage to BOH, LHR and LGW.
If and when they announce it that will mean that EZY have gone from having no presence at SOU whatsoever to competing on the busiest ski and sun routes from there in just over a year and a half.