I'm not sure the distinction that you're making between "distributed" and "decentralized" is commonly accepted in the research community (or broader technology

I'm not sure the distinction that you're making between "distributed" and "decentralized" is commonly accepted in the research community (or broader technology community). In this context, the authors appear to be using "decentralized" to contrast with the "centralized" nature of leader-based state machine replication protocols.