I did a talk on anger in the workplace at SREcon22 to an audience of people who work in tech [1]. Anger is well-studied, particularly by Dr. Brad Bushman, who has made it his life's work.
It's important to draw a distinction between repression and expression here. Feeling anger does not need to equate to expressing anger, though we often do. Expressing anger is almost always harmful—I'm hard-pressed to come up with an example where it isn't harmful—both to the individual feeling anger and to whomever they may express it to.
Dr. Bushman found, over multiple studies, that expressing anger led to a heightened state of arousal and set the conditions for its reoccurrence in the future.
The middle way is to feel the anger mindfully. One can even discuss it. The distinction is in becoming the feeling (I am it) versus recognizing the feeling as a guest who soon will leave.