WN did not have 100% reward availability prior to March of this year, and I'm sure the data is from before then. And even then, only reward availability from points earn starting March of this year is 100%; WN has a mix of old and new awards right now, and the old awards are nowhere near 100%. (Well, the old awards a mix of two types in turn, but most people have the type that are nowhere near 100%. The other type, which is double the former, is still not 100% because of a handful of blackout dates.)

WN's new system trades reward availabity uncertainty for reward cost uncertainty. At most legacies (DL the big exception), you know it'll at most cost you double, and in fact for any destination there are only about two reward prices (not countiing Citi discounted awards at AA and such). WN's new reward cost can change daily, even hourly, every time the cash price of a flight changes.

It's actually AA (and most other legacies) that have 100% reward availability at only double the cost. But once again, it's a question of cost for most people, not just availability.