Adventurers matter during an invasion. My advice is to keep an eye out. Often times advies start finding invasion-related items that are critical to being able to stop it.
If by "often times" you mean "only in the third invasion to date"...
I'm not saying don't keep an eye out, but you shouldn't hope too hard that the macguffin will appear through adventurers. The third invasion had portal stones found by adventurers, the fourth had the Light and the Avatars. Who knows what this one will have?
