I only see this helping the lag, since more people would be sparring, and reduce the afk amount around graal city.
The only problem I would see is if it were to get a lot of people in the same rooms, 100+, then maybe if all the rooms were connected, and you could spar people that are in a different room. Then people would just pick any room, and get their quick spars going.
That way everyone scatters around, and doesn't cause lag.