It's a good idea, but I don't like the way it is set up. Having a centralized service store your encrypted message, which will presumably be your seed phrase, and handing out the decryption key to your family and friends is the wrong way to do things.
Yeah I know, its not really ideal, just one of the options.
Much better to give your family and friends your encrypted seed phrase, and have a third party service store and email out the decryption key.
True, that's a better way. For me personally just giving seed phrase to my wife and parents works fine, but I know that not everyone can trust theirs (which sucks I might add). My wife asked me (half joking lol ) do I trust her with seed phrase, to which I told her that I would divorce her already if I don't trust her with something like money.
I have my wallet keys saved on my hard drive and my son and wife have the password to my hard drive but are only permitted to use it on my instructions or when am not accessible to use it. This has helped me to secure my coins, I can't afford to risk my digital assets so I let my family have access to my keys and passwords.
But what if something happens to the hard drive? Just few months ago my SSD stopped working after only couple of years, thank God I didn't have any important data there and I don't wanna even think about what would happen if I had something as sensitive as wallet keys stored there. Sure, you can restore some data, but its a major pain in the ass and AFAIK you can't retrieve 100% of the data.
My point is, you might wanna consider saving those keys someplace else as well, just in case.