Actually, NAP is deprecated in Server 2012 R2 and may not be there at all in the next version of Windows Server.
First, note that RADIUS is simply a protocol for authentication, authorization, and Accounting. In Windows server (since Server 2008) the Network Policy Server service/feature provided RADIUS and NAP was built on top of this.
I don't think that NPS itself is being deprecated, just the NAP functionality that is part of NPS: https://technet.microsoft.com/en-us/library/dn303411.aspx. Of course, they may rebrand it -- RADIUS was formerly part of the feature set called IAS prior to
Windows Server