What you'll be missing is essentially two things - icebreakers/get-to-know-each-other activities to allow you to learn a bit about the people you'll be living with on your floor, and a quick rundown of the major rules of residence and how they're enforced (which is outlined in the Residence Code of Conduct and other policy documents - you can find those at
http://housing.mcmaster.ca, then Residence Admissions --> Residence Policies).
The first part is a nice introduction to your floormates, but not crucial - you'll be spending 8 months with these people, so you'll definitely get to know them regardless. The second is a little more important, in that you must know the things you are and aren't allowed to do in residence. If you've actually read the RCC, then you're probably ahead of most people (who don't seem to bother). The other important things to learn about are things like the guest policy and alcohol policy, which you can also read online. Your Community Advisors (CAs) will probably be more than happy to give you a quick rundown tomorrow of what you've missed, so I wouldn't worry too much about it. The nice thing about hearing it at the meeting is that they only really talk about the most important and relevant parts, and they may also give some hints about how they'll be enforcing the rules that year.
But really, you should be fine - just make sure you connect with your CA when you do move in, and they'll fill you in on what you need to know. Also, know that Welcome Week will be in full swing for you by that point, so make sure you get your stuff moved in fast and get out there with your building and enjoy the events!
