I can't comment on the reliability of Google Maps for Vancouver, but in general they show road closures. However, A couple of years ago in my hometown of Melbourne, Australia, both Google Maps and Waze showed entries onto a major bridge during construction when there were delays of over an hour due to closures. The entries were closed and I had to navigate around the city to find a way to get where I was going. Google tried to keep diverting me back to the closed ramps. Luckily, I knew my way around but a tourist relying on maps would have been lost for the day.
Having said all that, there isn't much choice, and they should get you where you are going, but you should compare the route with Apple maps, just in case.