This doesn't really make much sense to me, even if it seems like a pretty good idea.
Not inviting him may test him out in the area of loyalty ... otherwise this wouldn't be a problem for XGuard i think, i don't know. Trails in general seem senseless to me since it's already an invitation to the clan.
Let's be real, we all are too nice to throw someone out after he got invited. We would never do this. For me this idea seems to be more like an excuse for inviting him anyways, ignoring his ingame skills. That may sound a bit harsh, i really love XGuard, but i hope you understand what i'm saying.