(Oh well, the evidence... here, I let my dragon parked in double row, just wait...) *and he runs*
Unfortunately I don't have a screenshot of that, I was leveling up while I was about level 38 and cap was 40, I didn't care about dragons in Soul Gazes and I believed that was a normal thing (it was the same dragon that came out from Nyrol's Nest, a dungeon in the same map).
However even with a screenshot should be hard to demonstrate, but, that day, when I got it from Aryna's (I already got one few days before even from Nyrol's Nest) so I was a little annoyed to find the same dragon from different dungeons (this is what I remember :/).
(This and the German thread are telling that I'm wrong, and it's possible, but if I'm wrong... what's wrong with my mind that day ? I'm so sure of that ahahaha. Well this is a personal trouble ahahah)
(by my experience I can write that Blueberry spawns even from Aryna's Lair...)