2 issues with this :
If simply using retail store employees to scout around and "Report problems" from the app : while they're doing that, who's going to be serving customers in the retail stores ?
If taking user reports and simply updating the database, as pointed out, what if the mistake is in the integration of data from OSM or TomTom and the correction is eventually overwritten with faulty data ? I doubt retail store employees have the capacity/knowledge required to trace back the mistake to the source.
And frankly, if the problem is OSM or TomTom, the retail employees can't exactly fix that beyond sending the report upstream and waiting for an update/re-merge.
No really, this sounds quite fishy and desperate as a tactic. Unless retail employees are willing to work for free, you're going to lose 40 man hours/store where customers are now going to get even less service (I hate going to the Apple stores, the employees never seem to have time to get you what you need).