Christian_Balegrouse is technically open, there's a few features in the park. I was up today and had a fun time hiking the tube. Park crew been working hard lately with the little snow they have. I believe ticket prices have dropped for grouse.
I've never heard of any resorts giving refunds for closing early. I don't remember what grouse did last time they had to close early but maybe there will be a reduced price for next year's season pass (that happened to me when whis closed early for covid). I'd say there's a negligible (ie zero) chance they give refunds.
I had a pass in 2005 when Grouse had no skiing for a good chunk of the season. If I recall correctly they basically told us the mountain was still open for us to use the rest of the amenities so tough luck about the skiing. They may have extended the pass so we could use it in the summer, but we certainly had to pay for our passes the following winter. My dad wound up buying us snowshoes and dragging us up the mountain to use them a bunch of weekends because he was committed to us getting our money's worth. I'm not sure what they did in the more recent crappy seasons like 2010 and 2015 because I'd stopped skiing Grouse by then.
It looks like both Cypress and Seymour now have minimum day pass protection that you can purchase ahead of time (for 76 and 60 days respectively):
https://mtseymour.ca/tickets-passes/season-pass-reservations/pass-protection-60-day-guarantee
https://cypressmountain.com/season-passes/season-pass-guarantee