Earlier quoted context omitted.
Nitrate-free (or, "no nitrates added") bacon still contains nitrates. About the same amount as standard bacon, and in some cases, more. https://www.americastestkitchen.com/cooksillustrated/how_tos...
Better stop eating celery or anything containing it if you're really concerned about nitrates.
Sure, there's less protein in vegetables, so less chance of nitrosamines forming, unless you're eating a complete meal, in which case... figure it out.
Also, vegetables contain anti-oxidants and things which offset some of the nitrates, but this just seems like a reason to eat some vegetables with your cured meats.