"Uncured" is a marketing buzzword that typically means that the item is cured but that the manufacturer uses celery extract instead of Prague powder or Instacure. This is bullshit. It's akin to a chef using sea salt and claiming that their food is salt-free* (except for salt naturally occurring in sea water). Virtually all the "uncured bacon" you see in the store is actually cured. Check the ingredients to see whether it includes celery extract. Also check the salt content, since salt is part of the curing process. Salt-cured pork belly is no substitute for regular belly if you're trying to use it in a braise.
Edited to add: It may very well be genuinely uncured smoked pork belly. But whenever I see the word "uncured," my BS detector goes off.