How long after the event do you think it makes sense for this erasure to happen? Like, let's say that you are going to experience something absolutely traumatic but you know next week you won't remember it... is that also ok?
Not really though. Surgery typically uses anaesthesia that makes you not experience it in the first place, which is different than forgetting the trauma.
I don't think the human memory is well understood enough to say for sure whether consciously forgetting something means that there aren't still effects of your body having experienced the trauma in the first place. The mind, it would seem, goes deeper than conscious recollection, and perhaps beyond the brain.
Plenty of children abused before they can remember it still have exhibited signs of harm from the trauma.