Technically Evans is right re engagement. Pilot engagement improved last survey by 2-3%- from 21% engagement to 24%. In other sections of the company it does indeed sit above 80%- generally those areas that don't face the customer and have to do more with less. IIRC from the PWC love in, IT was quite high, as was 'loyalty' and a couple of those other touchy, feely areas. He's right about engagement being at record highs in those areas.
On the other hand, the pilot engagement results remain the lowest seen. Ever. Of any company in the world. Across every sector. If RIO had engagement that low at a mine site they'd close it down and sack the management. Oh, wait.
So see his article for what it is. A bunch of statements that are technically true, each targeted at a specific audience to create an impression that suits the current message. That message changes day to day.