Stoic you have misrepresented the 'debunk' -
What was debunked was, as you seem to acknowledge, the theory of stages... that grieving people worked through stages or phases of grief.
The feelings people bereaved feel still include anger, for some, but not all. That is not in question. That you feel there should be some containment of that grief is your opinion. Not born out by the experiences of many who have experienced the suicide of a loved one.
Maybe the issue is in trying so very hard to make the visceral reaction fit into our sense of 'normal' and acceptable behaviour. That we don't like the idea that any one of us could be so inexplicably wrong as to actually blame someone for being so ill. Well, as posters including myself have tried so very hard to explain clearly, it happens.
Misdirected anger happens, and is something the person expressing it needs to be allowed to express and acknowledge. Why would you deny it, deny them the space to fully come to terms with every emotion they are feeling? Everyone acknowledges that the anger is misdirected... no one suggests it is tight or healthy to maintain that anger, that blame.
The only unacceptable thing written here is your statement that someone elses expression of emotion is wrong.