This happened a few days ago, but before I vanish into the black hole of my pending vacation, I wanted to post about it.
My wife and I were farming in the Sanctuary of Zi'Tah, when she sudden gasps. I look at her screen, and she's targetting and clicking on a Mog Tablet. We both absolutely freak out! She was so excited, giggling like a little girl. She headed for Jeuno to collect her reward.
I decided, for the hell of it, to head to Ro'Maeve. I began searching as she reached the moogle in the Gardens to pick up her ring, as well as getting a Noble's Bed. I didn't hold a lot of hope of finding one, so, I turned and headed for the zone when I saw a sparkle in front of me.
I targetted it, and up pops Mog Tablet on the screen, I click, the tablet spins up from the point and flies off. We were both yelling and happy at the unexpected EXP windfall! And right before our vacation together!
So, it is possible to get these rings, you just have to be in the right place at the right time.