This seems like double-talk to me. The talk is about decentralization, but also bakes in the idea it will be done exactly to their specification. Nonsense, of course.
As Satoshi Nakamoto noted: "The nature of Bitcoin is such that once version 0.1 was released, the core design was set in stone for the rest of its lifetime."
I can imagine Dorsey wants to strive for the same thing: build a protocol in such a way that it becomes very difficult to change key aspects of the system.
Not to mention mastodon already exists.