Metallica played Club Hípico in Santiago, Chile on April 27 (yes, that show) and is seemingly posting a handful of performance videos. First came "Spit Out The Bone" from their 2016 album Hardwired… To Self Destruct, and now we've got "Through The Never" from the eternally-popular 1991 Black Album. Check that out above.
As for what Metallica has been up to lately, hopefully it involves new music? Guitarist Kirk Hammett was recently asked why he chose producer Bob Rock to mix the songs on his solo EP instead of usual Metallica engineer Greg Fidelman, and his answer seems to hint that maybe Metallica was up to something last summer.
Hammett mentions Fidelman twice, saying he "had his hands full with all sorts of other Metallica stuff" and "he was up to his neck in other Metallica commitments." Of course that could be mixing some live material or even working on the Load and Reload box sets… or maybe it was new music?