Hi everyone! a friend of mine called her venue today and they provided her with some insight on why venues havent opened even though restaurants have. So heads up if you want to postpone they suggest October since things for Sept have been canceled. Here is what she said. I hope this helps 
I got some insights while speaking to a vendor today. A common misconception is that banquet and convention centres are the same category as restaurants; they are NOT. Convention centres fall under the same category as concert halls which are not due to open up till Phase 3 in Ontario. The vendor I was speaking to was very honest and suggested not to book anything even in September as phase 3 might have strict restrictions even as late as this fall. They said most people in late August and September have cancelled their events so far.
