This is partially true. The use celery extract or whatever they can get away with legally. Smoking is what gives bacon the flavor. Buy your cut of meat, season, and smoke it with a very low temp for long time, you have bacon. No nitrates.
It is weird to me that people try to make an issue out of this, because it's not like the flavor change in cured meat is hard to miss. Just buy some pink salt! Corned beef tastes like corn beef because of nitrites.
I get that you like smoked pork belly. I do too. I don't even object to you calling it "bacon". All sorts of things that aren't American bacon are called bacon. But nitrites are absolutely part of the distinctive flavor of American bacon.
The whole thing is silly, because we can just point to ham and corned beef, two products where the debate doesn't even make sense; we only see it with bacon, and we only see it because vendors lie about whether their products are cured.