Perhaps. I don't know anything about how Netflix does their design. But the underlying point was that implementation details change, technologies change, and it's hard enough to keep up with the changes while you're focused solely on development.
I'm not opposed to individual designers learning how to code, but my fear is that the industry will come to an expectation that designers should be able to build UI's. I think that's a very very bad idea.
The expectation is already there. I feel sorry for designers who simply worked in html who's lives keep getting more difficult. At one point you drew in photoshop/sliced then you had bootstrap which would give you a base but you needed to override styles.
JSX makes a lot of sense for those writing components but makes little sense for a designer to be forced to think in that way. Using vue with html templates allows designers to copy and paste html.. it's not that easy with jsx..
I'm not opposed to individual designers learning how to code, but my fear is that the industry will come to an expectation that designers should be able to build UI's. I think that's a very very bad idea.