I don't see what the big deal is...
Quote:
Before the update, a player who fought a monster without using auto-attack would retain his claim on the monster, even if he was KO’d in battle due to poison, etc. This has been fixed so that when the player dies, the monster becomes unclaimed.
I highlighted the important bit.
Basically, the bug was a mage, ranger, or other class with some form of distance attack that can be used without engaging the enemy could hold the mob for an unusually long period of time after death, since they wouldn't lose the claim immediately. If a melee character were to engage the mob, when they die, they automatically disengage, and the claim is lost as soon as they die.
All they are doing is fixing the claim rules for mages/rangers so that it is consistent with the claim rules for the melee classes. It makes sense. You shouldn't be able to hold claim on a mob if you are dead.
It shouldn't make a difference with respect to MPKs at all. If you're solo, you would have lost the claim eventually anyway. It would just take a bit longer. If you're in a party, if you die it won't matter, becuase the rest of the party should still be holding the claim.
Unless your strategy was to purposely die, then reraise while still holding claim, I don't see how this really affects anyone.