I discussed this with my FC mates yesterday after one of them mentioned getting an Atma crystal on nigh every FATE that they've done. We've discussed the increased drop rate, as were mentioned in the patch notes. Though the rate has been increased, I'm quite sure that it is still possible to not have the favor of the RNG gods and have zero Atma crystals drop after doing tents of FATEs over the span of ten or more hours.