Since this word only appeared very recently, you should explain it to people, particularly if you want people to use it.
But as a strong leftist for fifty years, what is the point of this? We already had a word for this — people of color. Are Blacks suddenly not people of color? Who are these indigenous people who are not people of color?
I feel we on the left spend too much effort playing word games and far too little doing, well, anything of consequence. We have lost, and lost, and lost, and lost for generations, and yet we learn nothing and spend our time on meaningless semantics. The world is collapsing around us; saying, “Let’s coin a new word that means exactly the same as an old one for no apparent reason,” is an terrible use of our time.
Therefore I will not be using the word BIPOC.