All this speculation on who might come to SOU is based on the masterplan being implemented asap!
At the moment it's all supposition,and 2019 is looming,so SOU will keep plodding on and on the basis of recent pax numbers is likely to fall below 2million.Until stands are created,runway extension in place coupled with taxiway and infrastructure built.
It's going to be a very similar 2019 to this year.