Is that true? I'm racking my brain, and most of the examples I can think of off the top of my head are enclosed. The various pavilions at the zoo, the Atlantis pavilions at Ontario Place, Victoria Park Pavilion, and the World Expo country pavilions. On the other hand, if you plug pavilion into Google Image Search, the overwhelming majority of results are open-air shelters. I guess it's just an ill-defined term.
I actually have to give credit to whoever organized the session. The building is probably as close as you can get to the trail as possible for a bookable venue, it's central to the areas being studied, and the time coincides with when the trail likely sees the most users. The time of year isn't ideal - a lot of seasonal users will miss it - but it's not like you'd delay something like this to summer. Hopefully they put some signs on the trail encouraging users to divert over and take a look.
I actually have to give credit to whoever organized the session. The building is probably as close as you can get to the trail as possible for a bookable venue, it's central to the areas being studied, and the time coincides with when the trail likely sees the most users. The time of year isn't ideal - a lot of seasonal users will miss it - but it's not like you'd delay something like this to summer. Hopefully they put some signs on the trail encouraging users to divert over and take a look.