I think the little teasers they play after encores are just that, teasers. When Metallica played Casper, WY in '04 and I saw them, they came out for the encore with Kirk strumming on Black Sabbath's opening riff of "War Pigs" and when I saw them in Denver last year, they came out for the encore and jammed on Mercyful Fate's "Into The Coven" for a little bit. That would be cool if they played The Judas Kiss sometime, I also read they played part of "Frayed Ends of Sanity" as a teaser at a show not too long ago. Now THAT would be pretty cool to hear...
4/19 - Danzig w/ Doyle, CoC
5/14 - The Dillinger Escape Plan, The Faceless
6/4 - Alkaline Trio
7/5/2019 - Iron Buffalo