Changes regarding the difficulty of Extreme missions

Hi. I've noted that most of the "Gousetsu" quests (Requiem, Karna, Vila, Moral, Adubuta, etc.) have been difficulty-downgraded on GameWith Wiki lists. The vast majority went from 13-15 stars to 10-12 stars. Is it some kind of event? They reclassified them because these quests became easier to do? Should I take advantage of max luck those monsters? I have been searching and so far I have not found any mention through official channels. These missions have always scared me as they are difficult for me to do even if I have 1 or 2 recommended monsters.

Any news regarding the subject is welcome.