Since PTR is now open for everyone and if the current build is an indication what to expect in the next week (which is not in any better shape than beta), I’m really hoping this is an oversight that will be addressed: None of my characters that have earned a 310% flying mount during Wrath have a 310% flying skill learned. This means I have to spend 4000 gold to get something I already had for the past year.
Please tell me you’re not screwing us up like this intentionally.
In beta you have to purchase it, regardless of the mount.
Yes, both Beta and PTR are the same build version and behave the same regarding flying skills (except for Azeroth flying not being available on PTR). Also both are plagued with the same bugs, unfortunately. Makes me really worried about the release. 
I wasn’t until the PTR.
I expected the PTR to have actually fixed the Beta issues, yet here we are.
I hope this is fixed.
I have seen some druid that was able to flight in Azeroth with his flying form in PTR. Maybe you can try if it works.
I can confirm that you can fly as a druid in Eastern Kingdom in PTR now.
Yes, tested that myslef on a druid. However that’s just druids, no other class can. By the way the same applies to Dalaran - you can switch to flight form anywhere in Dalaran, but you can’t mount a flying mount at the same spot. Looks like a big oversight.