First off, I like to state that Michael Saylor sounded like a self-centred person there. Why wouldn't someone have a plan to pass their Bitcoin to a heir, friend or loved one if they knew they were going to die at a particular time like he stated? That's pure selfishness.
I am also curious about that but I think that he's only saying this for publicity stunt. He's a rich guy and if ever it's not about Bitcoin, there is for sure some plans or inheritance already that are set for his kids and family. These rich people don't just want to let their wealth be put into waste and that's why if I am thinking what he is thinking, they won't get BTC but they'll get real estate, bonds, savings, etc. that he's already set for them if ever he passes away.