I don't think there's a way to do this out of the box, but you can deploy something functionally similar quite easily if you geocode to the centroid. We are doing this with countries, but I see no reason why it couldn't work for states/provinces or similar.
You will need to create a custom geocoding service. It's pretty simple. Take whatever polygon layer (e.g. US States). Convert that to centroid. Create a geocoder out of that point layer and publish it. Point SharePoint and your Location field at it. So they wouldn't be able to hover over 'Oklahoma' but you'd get a marker in the middle of Oklahoma they could hover over. Combine that with decent symbology of your borders and it seems functional to me at least.
Only thing to watch out for is cases where you have a very geographically dispersed polygon. For example if you take the "US" and create a centroid you may end up with something weird since it'll include Hawaii/Alaska/etc. So you may have to tweak it a bit, but for most admin boundaries it works fine.
