Changing the representation of location from place to region would not be helpful for us. That said, there is another discussion about reworking the location table for other purposes here.
The issue isn't 'how can we relate a region to a person' (person<->location history<->location<->coordinate<->region). The issue is 'how can we represent these spatial concepts in a proper and consistent way in the CDM'. We've been struggling to find any existing person-level vocabularies that could be leveraged, which also has a relevant post here.
In other words, the coding exists (census, EPA, etc) but it represents the concepts at a region level which isn't directly translatable to the person level (e.g. poverty rate for census block != person lived in area with poverty rate) . However, for the most part, the data be adequately represented by a combination of concepts from existing vocabularies, though it is unclear if and how this should be done. (Discussed in this post and, according to the issue list, it looks like THEMIS group 1 plans to discuss it)
There's a lot of relevant posts at the moment