I was initially excited to see this until I actually tried to price out the itineraries.
I tried a few destinations and from what I can see it still is cheaper to book EY than it is to book an EY-operated flight, even originating elsewhere.
Of course, I haven't checked every permutation but these codeshare agreements typically don't result in lower fares. They are great for the bankers and McKinsey consultants whose companies just pass on the bill but for the rest of us mortals, even the relatively affluent ones, they are a net negative.
As for redemptions it remains to be seen but partner redemptions on FB aren't the norm and I doubt that premium cabins will be cheap.
I'd love it to be like AA's redemption levels on QR but I suspect it won't be the case.