I've never come across flour-dusted dried fruit before, either, but I've heard that you need to watch for it.
I did, however, once come across a package of pumpkin seeds that listed flour in the ingredients list. I don't know what the heck it was doing there, but maybe it was for the same reason they would use it on fruit - to prevent sticking. I was incredibly disappointed because I love to snack on pumpkin seeds. It wasn't a main brand. It was at the County Fair at one of those booths that sell their own packaged product.
The experience was a good reminder of a rule I occasionally forget to follow: Check every label to look for gluten. It's sometimes hiding in foods you would assume to be GF.
CarolM