Star Trek never rehashed their own stories before now (actually even '09 isn't a rehash, but STID clearly is).
Yeah ... no.
TMP was blatant in its 'rehashing' of "The Changeling." "The Naked Now" ripped off "The Naked Time." The one with Pulaski's rapid aging is too reminiscent of "The Deadly Years" to be a coincidence. And so on, and so on ...
It's been said that there are only so many stories to be told. Eventually any franchise is bound to revisit one of its own.