Microsoft can't carry everything forward from release to release. Either from lack of use, replacement by newer technologies, or decisions to simply cease support, some features fall by the wayside of every release. In Windows Server 2012 R2 Preview, 64 features have either been deprecated or removed outright.
Microsoft moves on: Features removed or deprecated in Windows Server 2012 R2 Preview
SYSVOL's NTFRS replication, DFSCMD, Network Access Protection, Windows Server 2003 functional levels bite the dust