To keep this up to date, those of us with a GA travelcard have been offered the value of 15 days, which will be deposited on our Swisspass accounts. I think it's a reasonable offer in view of the situation and am happy with it. As I said elsewhere (Deutsche Bahn thread), I think the rail companies have handled this quite well. The refund process on the DB website works instantly, although you get a voucher rather than a refund, which is valid for 3 whole years. But the train companies will still be here after all this, no worries there.
For the Swiss SBB offer, here is the relevant page in English:
https://www.sbb.ch/en/travelcards-an...-pandemic.html