AC had contracts to hire x% from their feeders over the last couple of years. They have mostly gone through their requirements and have began hiring from the street again. I'm told a new posting should come up again near the end of the year. I'm told they have a good solid pool of people they're trying to flush out right now. Most of those are coming from WestJet, WestJet Encore and a couple of other off the street smaller airlines and charter within Canada.
Upgrades can be had in about 18 months if you take the first available slot. They start getting the first of 100 new 737's next spring. Rumour has it that the captains will go super junior and possibly right to new hires. Again, you may have to take what ever base they are at.
The 5 J class seats refers to upgrades when you travel standby. They will no longer upgrade anyone when traveling unless you use one of your 5 tickets per year. I think (but don't quote me) that they would rather go with those seats empty than 'upgrade' an employee or recriprocal/ZED pilot.
Thats what I know as of now.