The unlock law making it legal to unlock phones once they are out of their contract is in effect now (all of it must be fully implemented by Feb. 2015) but will need to be renewed in 2015 or it will go away, so I don't see Sprint changing policies or Apple changing Sprint's iPhones in response to this in early 2015. If Apple does change the phone for Sprint use to be "unlockable", then that will likely be done upon the iPhone 6's introduction in the Fall, or it might have to wait until Fall of 2015 (iPhone 6s).
Sprint's iPhone 5s's are not compatible with any other US carrier, and are CDMA, meaning that if they are unlocked by Sprint, the only other carriers that they can be used on are in Japan. For the iPhone 5, one model was compatible with both Verizon and Sprint (and KDDI Japan). Maybe the iPhone6 will go back to having one model being compatible with Verizon/Verizon/Japan?
I don't think Apple will come out with a new model mid-cycle (Feb 2015) just so some Sprint users can have them unlocked.
Even after reading the official info here, it is hard to understand exactly what to expect out this law
http://fcc.github.io/device-unlocking/
Also, Sprint currently claims that all of their Apple devices are technically incapable of being unlocked.
http://www.sprint.com/legal/unlocking_policy.html