I think you're a little confused as to what exactly's going on, it's not a public display / event like shown in the video, the vid is just there as an example of what is going to be built as they'll be using the same builders. So all riding apparatus will be open to everyone, as far as I can make out there is no 'public'. It also seems like it's going to be mainly TF members / bike trials community. It's basically a big as well organized group ride.
(That is as the impression i get from this topic, i could be wrong)