If you had a room-based cp/gq and one of the rooms was unmapped, but there was an identically named room that was mapped in another area that was out of range for the cp/gq, you would get no entry in your targets table. This small change makes it so that in this case you will still get an "unknown" entry. It won't help when you have multiple rooms in the same range, some of them unmapped, but at least you'll still have an entry in the table in this case, even though it may be the wrong one.
If you had a room-based cp/gq and one of the rooms was unmapped, but there was an identically named room that was mapped in another area that was out of range for the cp/gq, you would get no entry in your targets table. This small change makes it so that in this case you will still get an "unknown" entry. It won't help when you have multiple rooms in the same range, some of them unmapped, but at least you'll still have an entry in the table in this case, even though it may be the wrong one.
Before (simulate cp at level 15)
Same cp at level 14 after the change: