if you follow my other articles you will find that I have described Khipu, an architecture written in DDP. Initially it was meant to implement Robert C Martins Clean Architecture — classical OO. By adding immutable models and state it indeed became reminiscent of Flux/Redux based systems. In my case I had been exposed to TEA (The Elm Architecture).

I also want to point out that DDP isnt FP, as DDP uses partially applied functions for state keeping — in other words side effects.

Yes, your observations for similarities are correct, even though I started at the other end of what many perceive as a spectrum of paradigms. In the end it doesn't matter what paradigm we follow — the underlaying machines and the math are the same: certain characteristics will emerge in our systems even if we take different path.