Sure, but it's also how a lot of non-brutal regimes keep laws from growing out of control with silly edge cases.
If you are harassing someone, law enforcement doesn't have to consult the legislated list of 23,784 actions that constitute harassment. That seems reasonable.
The clarification that you just quoted above from the Director of Public Prosecutions is only one sentence in length but it would entirely change the meaning of the law, if a clarification like that were actually in it.
US harassment laws are not a list of 23,784 actions that constitute harassment either. Here's an example of one state's law. It is clear and specific, something all laws should be: https://definitions.uslegal.com/h/harassment/
You might be interested in this programme (from 2013, so there have been some changes since then) that explains how it works: https://www.bbc.co.uk/programmes/b01sn9cf
Implying they already expect to reevaluate this decision?
While this statement sounds reasonable at face value, these kind of important distinctions really need to be codified in law, not left up to prosecutorial discretion. Vague speech laws plus a great degree of prosecutorial discretion is exactly how a lot of brutal regimes oppress dissenters while justifying their actions.