This is interesting, although I suspect it won't make much difference for me in practice unless they devalue their FFP. I fly a lot with Alaska Airlines and earn their miles (at least 1 per mile flown, plus elite bonuses and frequent promotions). Last year they had a 2x points on transcons promotion. I was earning 5000 miles (+elite bonus) on each $115 SFO-NYC flight. 5k was enough for a redemption inside California, even if you had a creative stopover. For instance SFO-SEA one day, SEA-LAX the next (an itinerary I needed a couple of times).
Or you can use 25k AS miles for a transcon on AA business class on their A321T.
So I think I'll keep using my AS membership when I fly with them (upgrades are another consideration).