I'm pessimistic and think, sadly, that you have too much faith in the patent office.
The correct response to this doesn't even have anything to do with "an abstract idea" - it should be "You have a device that is designed to take pictures and can identify objects in those photos, and that device has location information and storage. Using that device to keep track of the locations of objects is obvious - not patentable.
The only thing patentable would be if they had some novel way of storing location information perhaps, or some novel method of object recognition. The "idea" "keep track of objects' locations with a hololens" should not be patentable at all.