Psychologist here. Anger and optimal responses to it is a complicated issue. There is research (involving randomized controlled designs) suggesting that approaches to anger where you "act it out" can actually fuel the fire, like you're suggesting.
However, it's complicated because these studies generally focus on length of emotional response rather than complex, downstream effects. That is, they assume that the goal is to stop anger state; by that assumption, it's better to adopt a sort of distress tolerance approach than to act on it. But what about long-term effects on relationships and communication? Where does one draw the line? Stonewalling and cutting off communication is a strong predictor of relationship dissolution for example, even relative to intense expressive patterns. So if your response is to always approach your anger robotically and to shut it down, does it then lead to passive aggressive responses, which can be even worse?
There's also an important distinction between anger and aggression, which are different and have different associations empirically, even though people tend to conflate the two. This isn't unreasonable, because I'm not sure at what point you draw the line.
As a parent of a toddler, this article had me thinking a lot, and I'm not sure what I think. Lying to your child, for example, is manipulative. Is it better to express your anger or to lie to them and tell them a monster will bite off their fingers? Of course a child who's cognitively not developed enough to understand will become terrified, because they believe it. But is living in real fear of a disfiguring monster over a minor transgression really less aggressive than simply visibly expressing anger? Or is it just a manipulative aggressive response on the part of the parent?
I really don't know the answers to these types of questions. I wish I did.