I'm not sure how many Walgreens stores were modified to support the build out needed for the Theranos labs but the relationship must be pretty toxic if they are considering eating the cost (unless they required Theranos to paid for said) of the buildouts and / or attempting to find a replacement that could utilize the same facilities.

The Walgreens I have visited that included Theranos required a rather large modification to the standard layout...not to mention the (speculating here) the legalities surrounding handling bodily fluids that you wouldn't consider in a typical pharmacy.