If VS cancel the flight you can have a refund.
If they don't and you chose not to travel the most you can hope for is a voucher.
VS will contact you if/when they do cancel the flight but only if you booked direct. If you booked via a TA then they are responsible and you will need to deal with the TA.
You need to be proactive in this as well and not just rely on the airline telling you things.
So check your booking on a regular basis and keep an eye on the VS website for their latest policies.