Factory Refurbs direct from mfgr's websites (not fleabay/'Zon marketplace), are usually ok and a good way to save a few $$, provided they carry the same warranty as new units.
I have done this many times over the years for all sorts of stuff & have never had any problems whatsoever with anything.
IMHO, sending in a unit which you bought new for repair/replacement under warranty, to the mfgr & them sending you back a refurb should be outright ILLEGAL everywhere in any way, shape or form, period. No if's and's or butt's.....
BTW, just exactly how does a mfgr "refurb" an SSD anyway (no moving parts to wear out), short of securely erasing it, checking the connectors, and giving it a good sanitary wipe down before putting it in a fresh A/S bag and box ???