Using roaches instead of crickets would be alright. Of course, the more variety you can offer, the better it is for the animal. Try to include at least 5 different feeders, making sure that no one feeder makes up more than 20-30% of the diet if possible. A mix of these feeders would be great for the animal: roaches, superworms (be careful as they are a little fatty and addicting,) silkworms, hornworms, butterworms, phoenix worms, mantids, crickets, stick insects, isopods, snails, slugs, safe butterflies/moths, grasshoppers, etc. Make sure anything from outside is pesticide free and non-toxic.
EDIT: If they used roaches, supers, and a couple of other soft worms, it would be fine. Just check out the poops. If the chameleon is healthy and free of parasites, and the poops seem to be watery, that would indicate that more "hard shelled" bugs need to be added for roughage.