Being the Fortune 1 company, Walmart is literally leading the way.
The only thing missing from Walmart's blockchain arsenal is 'Sovereign ID' management. If Walmart manages to acquire or file for patent for its own system, it can definitely stay ahead in the unmanned shipping business.
Blockchain based Drone delivery is not a new concept. An Cryptocurrency based Project called Dorado tried this last year. I am not sure what happened of this company, probably, another exit scam in the Cryptocurrency list.
Imagine what happens when Walmart is able to employ fewer people, ship faster than Amazon and reduce its 'transaction costs'?
All of those are possible with the sweet mix of Blockchain based drone delivery + Cryptocurrency settlements. A long term strategy is at play here and these are absolute exciting times for the space.