Often it is simply impossible to do anything constructive with anger. So techniques like the one in the article are useful, it's not a dismissal of anger as a valid emotion. The goal is to reduce redirected aggression.
Now there is an opportunity for you two to work through the issue, and the partner has to feel some of the emotional impact of their behavior, preventing them from dismissing it.
If that issue remained unaddressed, you might deal with the stress by reducing your view of your partner as a capable thoughtful individual, which is a much harder situation to address than a difficult emotional conversation.
And it's not just anger. If I want to express verbal affection towards someone and they don't want to hear it, we often call it abuse. But if they want me to suppress verbal affection towards them and I don't want to, we celebrate it as them having boundaries.
And I think sometimes being forced to not say something can hurt as much as being forced to hear something, yet we don't seem to see how it harms people.
But you can also process anger solo with the right tools, or with a good therapist that doesn't shame anger. It doesn't always have to involve another person.
Aside from academic interest, I struggle to see the practical benefit of this study. When I'm angry, in the heat of the moment, there's no way I'm going to stop and write an essay about my feelings. By the time I am in a frame of mind to do so, the anger has passed and not a problem anymore.