Why aren't there any blind tournaments in League?

One of the cool things about esports is that complete anonymity is possible in a tournament setting. Traditional sports have nothing like this.

What if for the next Worlds the tournament was setup so that every participating team showed up for every match at 5 computers but had no idea if they were going to play or not that day. Only the two teams that were to play each other (picked by a randomizer) would get their draft loaded up. The draft between the two chosen teams would then commence and only after it fully completed and the chosen teams were in game would the other non-playing teams be able to leave. Through this setup you could have an entire tournament where each team would have no idea who they were facing (at least until the grand finals).

I think we'd see some really interesting games if something like this was implemented. It would throw so much team-specific preparation and target-banning out the window.