I'm retired from the software dev biz now but have done plenty of work in enterprise apps and never had the opportunity (misfortune?) of working with React beyond occasionally evaluating it for projects.

What did catch my attention though, was this in the piece you linked to at the end:

"You’ll Be A Better React Developer If You Understand Functional Programming Concepts"

The one thing that is absolute about enterprise software development is that software technology is not static.

I think, based on your obvious deep knowledge and what you've written here, unless I'm misinterpreting, that the CTO very nearly threw you under the bus for his mistake.

What was that mistake? Easy - he didn't set up a training initiative for the software developers on his team who were unfamiliar with React patterns.

Frankly, by this point, it should be somewhat inexcusable for any JavaScript developer working on an enterprise project to be unfamiliar with functional design patterns. So the CTO is responsible for that negligence, too. It's understandable to some degree, because his .NET folks were obviously OOP-oriented.

One might think, well, how do you train a staff to get "functional". It's just not a problem with good developers. Trust them to catch on.

The CTO, instead, took a .NET staff, as I understand it, and it was almost like he was saying, "Hey, I've got this big Lisp software project I want you to work on. Please have it complete by tomorrow. And if you don't, I'm gonna fire somebody. But not me. I'll be in Bali. Thanks."