Knowing Typescript is enough to begin and start a career, you are sure to pick up relevant vanilla JS knowledge along the way. There is no way around JS: you’ll see it in tooling, debugging, building etc.
Of course you can really focus and grok everything way in advance, but I would argue it’s not necessary.
All software is political, riddled with biases and potential security risks. Most of the time we ignore the policy of the software, because we either agree with that policy, or are conditioned not to clock it as a “policy”, because “this is just Common Sense™”.
I suspect, if the author would have been more honest with themselves, they’d write something along the lines of “turns out, software is a platform for political action, and it scares me” - an opinion that is very valid, valuable and thought-provoking.