Eradication of identity view is a cause or effect of stream entry? I am asking this question due to this answer.

Is the removal of identity view (sakkāya-diṭṭhi) required before stream entry can be attained? Or would identity view be removed only with the achievement of stream entry?
To me this question sounds like an example of reification. In my opinion, in real life the numerous factors of Understanding and Liberation develop gradually, supporting each other in lockstep.

The more someone sees through the numerous simplistic assumptions underlying our idea of "self" - the more one can be said to be free from the self-view. In practice the stream-entry is gradual, just like Enlightenment itself (I believe).

The entire maturity model is pretty much a reification - defining clear-cut categories where even the criteria for delineation are not well-defined. This is why in Mahayana we are advised against obsessing over categorization too much, because it can lead to dead-end arguments, but also supports the self-view. On which level am I? - this very question already presupposes existence of "I" that can occupy a level.

I think the whole model is a bit sarcastic on Buddha's part towards the junior students (and Buddha WAS known for his sarcasm) in the spirit of "oooooh, sounds like you still have many more lives to go, brother" etc.