I think some intermediates can't or haven't tried doing Steve Garnsey. I would expect an intermediate to be able to do Woody's wonderland and Transec, but with difficulty and maybe a bit of help on 1 or 2 hills. I expect there will be some riders at the training course that have never done any of the 3 trails I just listed.
Instead of guessing, I re-read the original post. Here's a quote "We will be helping riders develop their abilities to do the following: •ride tight single-track, (intermediate) level 3 trails". The 3 trails I mentioned above are level 5. Oriole lake trail is 3+.
This is my opinion/interpretation, so take it as that. A level 3 trail is the main loop for the Boogie on the Saturday and Sunday in dry conditions. This doesn't mean you won't fall or get stuck. But you should be able to turn around and redo the climb or get yourself unstuck.
Kevin