Originally Posted by rkkwan

CO has been allowing BF cabins to go out with empty seats for long long time, with people on upgrade waitlist. Everybody here knows it, CO knows it, there are dozens of threads on this forum about it. That should change with the upcoming policy change with same day clearing of waitlist.

By itself, there's nothing to investigate or explain.

But the whether that other party was doing phantom booking, etc, is another issue. Maybe CO will try to find out what's happening, maybe not.