I have never seen anyone get in trouble for having swords there, other than people who buy the real swords at the con and then just walk around with them like it is nothing, I have seen that the last 2 years I have gone to Mega.
Besides that, Mega is pretty loose when it comes to props. I had my airsoft M4, with orange tip on it and I was told by one of the staff that it was not allowed, yet I saw people walking around with tons of different types and no one person said anything. I still went in with my airsoft gun and it was totally fine.
Just as long as you are not being an idiot about the way you carry your weapon or swing it around or waving it, etc., You should just be fine!
Also the bag rule is mainly for outside of the con area coming to or leaving the con. It is just so that people outside the con don't freak out seeing someone with a weapon.