Windstream can choose to accept or reject leases in chapter 11. It's either / or -- unless the owner wants to negotiate, Windstream has to accept 100% the current terms or reject outright.
Windstream filed a list of 30+ locations where they seek to get out of their lease:
http://www.kccllc.net/windstream/document/1922312190326000000000037
This does not include the big Uniti lease.