We originally reported that Dave Meltzer of the Wrestling Observer Newsletter noted that Sasha Banks was being kept out of the ring for long-term storyline reasons. 

However, this is coming into conflict with another report from Squared Circle Sirens who now claim that Sasha was injured during a live WWE Event on May 15th Charlottesville, VA, the same day Melzter's report came out. 

Banks teamed with Becky Lynch and Paige to defeat Lana, Dana Brooke and Eva Marie that night. Sasha has not wrestled since that live event. It's unknown what injury she sustained but it may have something to do with a fall on her head hence why she has been kept off television.

It's entirely possible also that Melzter's report was accurate up until that point and she subsequently sustained  the injury keeping her out.

UPDATE: Dave Meltzer is now reporting Sasha's injury

She got kneed in the head by a ref https://t.co/U7Xh038gO0

, Dave Meltzer (@davemeltzerWON) May 22, 2016