There's an endless number of possibilities as to what could happen in order for me to not be able to go online and verify with that link. Why would I put myself through the stress of potentially forgetting and now I have to worry about the secrets of my dying breathe being released to the public while I'm still around.
If I wanted anything to be taken care of I'd feel much safer keeping it in offline storage with a note attached.
What I think you should do is have a tiered level of notifications. For example an email every week is the first round of notifications. Then I wonder if you could pull my last login info from major services that are going to be around for awhile like Amazon, Google, Apple, Facebook(debatable), and if I havent logged into any of those services in 1 week, then go to the final round of notifications which is an in-person phone call.