Source: The Wrestling Observer Newsletter
According to sources, Samoa Joe and Sami Zayn could be headed to the main roster soon. The current creative plans involve bringing Joe up after after WrestleMania 32, while Zayn could be headed up for a feud with Kevin Owens after their Royal Rumble spot(s).
There was some alternate talk of Joe beating Finn Balor for the WWE NXT Title which would extend their feud and delay the call-up, but the current plans are to have him come up as soon as the RAW after WrestleMania 32 in Dallas, TX.
Finn Balor is not expected to be called up any time soon, as WWE plans to keep him as the face of NXT past March.