It's relevant in that the CPS might decide not to charge the MP - usually on the grounds there is not a reasonable prospect of success [in securing a conviction] - however, that should not prevent the Chief Whip from suspending the MP concerned whilst instigating its own investigation. This is because the woman in question claims an attack or attacks/threats took place within the confines and vicinity of Westminster Palace. So, whilst it might not mount up to a clear criminal offence, it might still be considered a serious breach of a minister's code of conduct and breach of HR policy.
The government's attitude, let the police sort it out, nothing to do with us, is an abnegation of their responsibilities towards the young interns who work tirelessly for their ministers.