I would say that this has become idiomatic. It means both present and future unwillingness to tolerate this and while it could as well be told in the present tense (used for general statements) it has somehow become established to use the future (also to stress the point - there also exists "We are not going to tolerate this!", but I think the use of "will" makes the message clearer and stronger).
By the way, a very nice little story with a clear message. Is that yours?
Student or Learner