As a returning player, I had no way to know they were going to zero out my Flightstones. Had I known, I would have used them. I read all the posts I could find from Blizzard about what to do before the launch. Nothing was mentioned about Flightstones being deleted. Blizzard also did not mention that Honor Points would disappear on August 22nd (they mention August 26th).
This is not professional of Blizzard to put out official lists that do not include items that will disappear. It causes frustration and the inability for players to complete items they were expecting to be able to complete.