The JP version has had "alternate" restoral items for quite some time. If Nutaku's treatment of these items is like DMM's, then they won't disappear at the end of this event but they will at the beginning of the next one, so they can still be used for that three- or four-day break between events.

But as Armeris said previously, whether or not you believe this will apply for Nutaku or that they'll even hold up to their own word is up to you.