Like they mention in the article, I also recommend the Uncle Nearest brand.
Uncle Nearest (his name was Nearest Green) was a slave who worked with Jack Daniels to create his famous whiskey. He was (I believe) the first black Master Distiller.
His descendants have created their own distillery. His great-great-granddaughter is now their Master Blender and man are those blends good. I went on the tour last year - highly recommend if you’re ever in Tennessee.
1, thats awesome. 2, they note gluten free specifically - which if they test for it (I really hope they do when they make the claim, because distillation does not guarantee gluten-free) means I've got a new whiskey to enjoy!
Added ingredients is the usual culprit, that said - some barrel pastes use a wheat base, which can then be a problem. Good ones use beeswax.
Some double distilled can be a problem for me. I obviously have no way of testing other than bad experiences, but I have yet to find a triple distilled thats an issue.
Short answer - "should" and "does" are two separate issues. "Should" isn't good enough when it comes to a medical issue, something I've learned the hard way with being gluten free.