Twitter do not care when women are being threatened or endangered.
A few years ago a female TRA with a few thousand followers doxxed me on Twitter. Published my email address, my name, and the city where I live. There was a whole thread with suggestions on who I might be - luckily I have a common name so neither she or her dim followers worked it out but it was really terrifying watching the thread evolve as various lunatics posted links going 'is this her?'.
Me and at least 50 others reported it to Twitter. In my naivety I thought they would take it down immediately. They replied instead within a few days saying that it didn't violate their community standards when it very clearly did. The tweet is still up there as far as I know.
The report in my case, and in JKR's case, will have been received by some basement dwelling TRA mod at Twitter who will have rubbed his hands together at women being endangered.