all those coins with the queens face supposed to be turned in?

I don't think so, sort of like how pennies didn't have to be turned in after Lincoln was shot.

they can issue new ones with whats his face on them?

I don't think England or Canada are interested in issuing coinage with a monarch on them anymore, they want everyone digital and controlled. Can't shut down a bank account consisting of nickels in a jar, if they're not happy with your political actions. They have to ensure the nickles are not valuable and make sure you can't pay your bills using them!

silver will be considered a national treasure.

I believe it's already a national treasure, spread all over the place, decentralized and ready for trade - if the people would accept it. But no, we like our ATMs and paper cash and electronic bill pay services.