This assumes the multiplayer levels would be designed with purposefully generating lots of lag in mind. I doubt they'd deliberately generate such an obviously grevious development flaw. If they did do HL2 multiplayer, it seems more likely they'd design the levels with the bandwidth demands in mind.
Or they could all get serious head injuries the night before and do what you said. They should release more info in the coming weeks, so maybe we'll all get to see exactly what they have planned.