The very first time you talk to a delivery moogle, it has some dialogue that something along the lines that the "tiny horned ones" (Padjal, most likely) convinced some moogles that they shouldn't hide behind their glamour anymore and become mail handlers. The owner of one of the chocobo stables in the Shroud has also seen moogles -- she named her stable after them in honor of being saved by one, but she hasn't seen one since then. Papalymo and Yda do not possess the Echo, but they can see Kuplo Kopp... and I don't believe either are from Gridania/the Shroud.
So... I think in the end, anyone can see a moogle, it just primarily depends on if the moogle WANTS to be seen. If a moogle is hiding behind Moogle Magic, then it takes something 'special' to see them (Echo or whatever), like in the Gridania opening scene.
So... I think in the end, anyone can see a moogle, it just primarily depends on if the moogle WANTS to be seen. If a moogle is hiding behind Moogle Magic, then it takes something 'special' to see them (Echo or whatever), like in the Gridania opening scene.