They can't actually label it "nitrate free", only a superficially sounding term like "no nitrates added", with the hope that people (like you) think it's the same as "nitrate free".
That's just the usual US marketing bollocks. Whether it is cured with nitrates or with celery extract, bacon is definitely cured. If it is not cured, it is not bacon.
I am more sympathetic to the term "turkey bacon" than "uncured bacon".
