I think if you can't verify the ingredients on the item that you're going to use, you should skip it - only because, like ham, sometimes there's incompatible ingredients in the item... If you buy from a reputable butcher, they might do their own smoking and be able to let you know. We definitely can't make blanket 'all are okay or all are not okay' statements about this kind of thing since they vary so much by manufacturer and even by region.
I am starting my fifth Whole30 in January 2021 and have always omitted smoked meats from my Whole30. But I'm curious, are they compliant? While not on Whole30 I always use smoked turkey parts (i.e. wings, tails, necks) to flavor sides like collard greens and green beans (which are compliant) but I was never sure about the smoked turkey so I omitted it. Trouble is these meats rarely come with an ingredient label. A Google search shows some brands with ingredients listed as water, salt, and sodium nitrite. If this is all, I can use them, but does anyone know more about how these meats are processed and if they are all compliant or should I continue to avoid them?