Pretty much.
There are attributes of blockchain implementations which are desirable attributes to solve this problem, but they can exist outside of block chains.
In fact, it's part of why I find this Quantum product interesting for this... they seem to have those qualities that would be helpful without bring much of the other baggage.
The only thing that's not clear is how you handle authority (who says who can participate, for example). So I don't think this Amazon approach is the complete answer, but this sort of approach seems like a path which might bear more fruit than trying to implement blockchains for the problem.