The comment about having people only in the main hotel was for those with rooms. Last year they didn't give rooms to the convention go'ers first, so there were a lot of normal people having to wait on elevators and such. This year they were trying to make the main hotel just for the convention, that way we didn't hold up the regular people or get in their way. The executive tower is holding events on multiple levels this year, so to say we are not allowed would be incorrect.
On the other note, I don't know the amount of space they have open in the lounge or if they want us hanging out there making lots of noise (or spinning an annoying bottle every few seconds for over an hour lol.) We could still use it as a backup meeting spot in case of rain, and then figure out what we wanted to do from there. I know that the executive tower has an outside patio over looking the streets on one of the lower levels. I never saw anyone out there last year, though that might be because of the rain.