@necator -- from your experience, and if you have the time, a list of types of "moiree-critical things" would be very interesting. We hear and see often this effect from repetitive fine patterning on fabric. What else?
For me it's fabric ... since I do mostly sashion and science. Within science I experienced no problem to date, with fashion sometimes it can be a issue, esp. when doing lookbooks, where you can't change the distance to the model, since each picture has to look alike. (Still the 5Dc has a AA-filter, so without it it would happen more often).
Which clothes: Hard to say. Of course those with fine patterns, made out of the threads. But not with all. Sometimes hard to predict. However it happens seldom enough to not really beeing worried about it.
Most times I also saw it together with the Canon 100mm f2.8 @~f5.6. (So, lens must be pretty good at resolving fine structures also.)
Oh, and forgot: Never had any Moiree on my leisure-pictures (family, holiday, parties, ...)