I'm sorry you and your wife are having to join this club that does have wonderful members. Many people are decades past a TNBC diagnosis so it is possible to have the same outcomes as other forms of breast cancer, especially with more treatment options becoming available. I don't think most medical professionals use "cured" for any form of cancer, but instead consider NED (no evidence of disease) the most positive outcome. The aggressive nature of TNBC does mean that chemo is typically part of treatment while it might not be for those with a tumor of the same size that is not triple negative.
I am almost 5 years from having a triple-negative tumor removed and have a friend with a similar diagnosis and treatment plan who is now 15 years out.
As to your wife's concern about other bumps, she will likely feel that way for a long time -- possibly for life. Time is not necessarily a factor in those being actual tumors or not, but the good thing is she will be seeing an oncologist frequently for the next few months so she can mention her concerns to someone who can examine them. Nothing is really going to reduce those fears except perhaps time. Best of luck to your wife (and you).