Just trying to understand this a bit better.
Are you asking about the legal situation? Or the commercial one?
If the weather is below limits before you leave, and likely to remain so, certainly my employer also knows how to read a forecast, and they make the decision on whether to cancel, divert, or "give it a go". I, as Capt, take enough fuel to both legally and prudently carry out their wishes as best possible. If my employer has not seen the weather, I would not just head off, but check what they wished for...
What decision the operator makes is complex - they are not just looking at this flight, but the knock on effects.
Looking about this all seems a non-story and standard practice across most airline.