That was also a patch after the gear cap was 90 and myth gave max ilvl gear and they released 3 fights at once. After that point (2.1) primals only dropped stuff below cap (that being ramuh an shiva, since levi didn't drop anything). I wouldn't count a one-off thing they did at the beginning and then renege for every primal after as the rule. In fact, ultimate weapon and LoTA dropped 80 gear and it actually felt out of place that the 3 remaining missing 80 gear dropped from the primals (earrings, second ring, and bracelet) were 90 instead of 80. It was probably a mistake they caught too late and just bothered to roll with it, seeing as their future pattern supports this.