More directly, if we look at Movies Anywhere's T&Cs [1], here's the main description of your license:
«Within the Territory and subject to the terms and conditions in these Movies Anywhere Terms of Use, Movies Anywhere grants you a limited, personal use, non-transferable, non-assignable, revocable, non-exclusive and non-sublicensable right»
I am not a lawyer, but the keywords there seem to me to be non-transferable and non-assignable. That is meant to keep you from reselling movies unlocked in your account, but also implies that the right is not inheritable. So too, the words "personal use" may imply "you and only you". Though that is a fun gray area in the terms because the system allows family accounts that bend past "only you". That's also why there is gray area in inheritance cases. The T&C as written would seem to me to bind only to you, not your family. Disney has the right to suspend your account for any reason at all, according to the T&Cs, but if they did need a reason "your death" is pretty clear because at that point the T&Cs no longer apply to "you".
Again, I'm not a lawyer, but this seems a pretty big and ugly minefield for digital assets that I would love to see more frank conversations about. I think it is a missing EFF plank, at the very least (and I've mentioned that with past donations).