I had to think about that, but I don’t think it is implausible. I think there could easily have been separate groups of people who walked that trail where multiple people in each group got sick, and the only thing that tied them together was that hike.
I get what you're saying, but there had to be other commonalities. 24 people out of how many who hiked it? How long between exposure and onset of symptoms? Was this really norovirus, or something else? Homeless people and squatters are all over the place now, if this were a likely scenario, you would think it would have occurred in a more populated setting first (and maybe it has, but I haven't seen the stories).