The "rare" pearls are simply ones which dropped from very high level creatures. What changed was that combat upgrade altered the levels of creatures. So where a pearl might before have been considered "premium" because it dropped from a level 287 creature, now it isn't considered premium because the creature dropping the pearl isn't level 287 any more.
The possible stats that a pearl can give you are the same, regardless of the pearl quality. The only advantage a "premium" pearl gives you is a better chance of getting higher stats. "Fixing pearls" would be a matter of changing the level ranges for different quality pearls. This would be a retroactive change which would suddenly change all the pearls in the game to be high-level pearls, increasing the power of Jedi globally and almost instantly - Unless we simultaneously lowered the advantage of premium pearls so that they don't give as much an increase to the odds of getting higher stats as they do now.
We would rather keep the premium pearls as they are - highly desirable and much better (in terms of the odds of getting higher stats) than normal pearls, but not drop them as casually as they dropped in the past. These should be rare, elite quest rewards and very high-end, elite-monster drops - not things that players "farm" from creatures that are no match for the player.