It could be. It's what I've been saying, anyway. But it doesn't mix with what people are saying - that when they get her up to super-high approval, that's when they get the random encounter.
But I'm figuring it has to be some type of low thing - or getting her too high too fast results in bugging it, similar to how that works with Leliana.
I haven't had a reason to dislike the random encounter quest triggers, since I never had a problem with them in Origins. I stumbled upon Wynne's the first time I ever used her in my active party with no waiting. Leaving whatever place to go wherever, boom, random encounter, and I'm thinking, Wow, I've never seen this one before. Same with Leliana. Get the right dialogue, go out and about with her, immediate random encounter and its hers.
Testing thus far with Awakening, it tends to require me going to six or seven different locations before I get a random encounter to trigger, at which point it's a random group of enemies - darkspawn, mercenaries, and bears, oh my! - to kill. Lather, rinse, repeat.