The big worry is that Easy would see the Island as a waste of time in the winter and come and go to suit themselves. They wouldn't nightstop a hull here, so when the eather turns bad, with early morning fog, the Island would be isolated with no first wave departures.
BE may fight Easy on one route, but if U2 really wanted to take the place from BE, they could simply because of their size and financial clout.
Once done, you'd be at the mercy of a carrier who really could care less about the Island- all it wants is flow through LPL to secure the best terms there for it's base.
BE makes money in Summer, like everyone else and swallows the light loads and losses in Winter. If Easy takes the summer off them, no-one wold step in and operate winter schedules without summer benefits, it makes no sense.
Thus the Island would be a ghost town and no-one but Manx2 would be left.
Ain't Open skies great!