It does not require or represent diagnosis of an individual
That's right. It requires a shitload more information than could ever be gained from these threads, though.
To think anyone could begin to assess risk with any accuracy online, unless someone outright threatened violence, is mind boggling.
In risk assessment, context is everything. The internet lacks any context as to the personal life of the poster. Judging words without facial expression, body language etc is not assessing risk. If the content of the language is explicitly risky, then fine. Otherwise, it's throwing assumptions at a wall and hoping it sticks.
That's why people spend hours on safeguarding children and vulnerable adults courses. But even they don't fully teach you how to identify risk. They focus lots on what to do once it has been established.
Identifying risk involves looking beyond the obvious, to the context, previous behaviours, identifying known risk indicators etc and using the relevant profiling tools.
None of that can be done online with any accuracy on a chat forum.