I'm not sure if this has been covered (only read back about 5 pages), but we had planned a quick trip to Vegas at the end of March to use a Delta companion pass and two free Hyatt nights. Cancelled Hyatt nights online, no problem, free nights back in our accounts (they had June expiration that stayed the same). I had to message Delta over FB Messenger and it took a couple days for a response, but they are refunding the fare we paid, giving back our companion pass, AND extending the companion pass expiration date until the end of 2020 (it was a 3/31 expiration, hence why we were going to use it soon). The rep indicated they are extending all companion pass dates until year end. Pretty painless process overall.