I have no experience or training recognizing suicidal behaviors. For better or worse, I personally wouldn't consider this question in isolation to be a sign that someone was considering suicide. If a pattern emerged then I would be more concerned.
To answer the heart of your question,
Should we assist people commit suicide, I'd offer the following thoughts:
The outdoors is a dangerous arena, and people who want to learn how to mitigate those risks must be able to ask about them.
We should generally assume good intentions, unless there is clear evidence that something nefarious is happening. For example I might suspect someone is more interested in hunting a hunter instead of a bear, but IMO until my suspicion is unambiguously confirmed my hands are tied.
If someone does unambiguously state that they are interested in causing harm to themselves or others we should notify the moderator team, follow up with the moderator team for status updates, and consider alerting local authorities if possible.
Also not to be too callous but anyone with a true desire to commit suicide, and the ability to travel to a truly wild area doesn't need our "help" figuring out a way to die. The wilderness will oblige their request without mercy, or compunction. There may be a Million Ways to Die in the West, but there are a million and one ways to die in the wilderness.