It's rather too late to add a retro gaming event to this year's timetable as the con book is about to go to print.
If someone were to bring an old console and games, it might be possible to use it in the Late Night Arcade event if Crome who is running it is happy to do so. There are a few challenges though. I'm not sure if the projectors and screens we have will work with the composite video and RF that old consoles typically output. We would also have to consider what would happen if the console was broken, especially if it was difficult to replace.
All electrical equipment used for events has to be PAT tested (this is both a visual inspection, so no cracked cases or frayed wires, and an electrical test) to make sure it is self. We can do this at the con.
Of course, there's nothing to stop you bringing a console and using it at a room party, providing you don't disturb people in nearby rooms.