Sadly, yes.
We went when my bil was on the mend from his latest cancer surgery, with a decent prognosis. I actually surprised my dd with the trip the day we left, in case we had to cancel, but my bil was doing so well, even fishing again. Unfortunatly, his tumor grew and caused a sudden, traumatic (in the medical sense), unexpected death.
We were on annual passes, so there was no ticket issue (so I don't know how Disney would handle packages). Disney refunded the unused nights at our hotel. My car rental ended up costing more for three days than it was supposed to for eight, because I lost my weekly rate. The airlines charged me $100 each to change the return flight. (Allowing me to use my really cheap fare was considered 'compassion fare', since I paid well below 50% of full fare.) Bottom line was that my three days ended up costing almost as much as my eight days would have.
But I have to say that the worst was the memories. I realized later that my bil died just at about the same time as my dd and I got our pictures taken at Epcot. I don't know if I can stay at CBR again, although it became my favorite the few days we were there. It didn't help that the night before, I became absolutely totally possessed with the thought that someone I knew died (I thought it was someone at work) and we'd have to leave. I never thought it was my bil. We all thought he had finally beaten his cancer.
Because my bil was seemingly getting better, it was a surprise. Had he been worsening, I would have postponed. It's not something I'd risk.