The problem is, they most likely have no way of telling if an item was created using the exploit. Therefore, it's more probable they just deleted all the +15s made recently. Even the legit ones if there were any.
How can they do that, and how do you know they can?
But if it's true then everyone is screwed.
If they can, they will need to go through server logs or something like that, which will be long. Probably like looking at every enhance over +10 and see it a rune was used up on the account at the same time of the enhance of +11 and over. Knowing nexon, they will prefer the easy, quick and dirty way. Which is: delete them all.