A vacant shop isn't a shop so there wouldn't be anything to map there. 

What you save by deleting outdated objects is that you get them out of mappers' way. Otherwise we might as well implement a policy of stripping outdated objects of their tags and then leaving them around, which I suppose wouldn't bother any end users and would satisfy the "keep the history" guideline, but I have a strong suspicion that that idea would upset more than a few mappers.