The SO contract is just a pay grade. They wear the same inform as everyone else and are refferred to as FO's. It only lasts 12 months anyway. When you're on it, you're an employee and more importantly can jump into the command process (which you can't do as a contractor) that is where (in theory) you can progress above the less experienced guys. EasyJet don't value turboprop guys. They never have. Sad but true. If I went to BA tomorrow theyd call me an FO on a 320 despite having 15 years bus P1 time. Not SFO, but FO. It's their train set.
I suggest if you can't take the concept of having a pay grade called SO then easyJet isn't the place for you anyway because there are plenty of more pressing issues to be worrying about on the inside. That's not a dig but if that really bothers you then the rest will ruin your happiness. Besides you could go to Flybe and earn 2/3 of the money trucking around on the q4 career killer as an FO ...but where will that get you ultimately?
Hiring FO' (or SO's) isn't causing any loss of sleep in the hangar. It's captains they are more concerned about although pretend that's in hand. When you all stop applying they'll start taking notice...and so the laws of demand and supply roll on.