By remotely I don't think they meant a long RJ45 cable connected to nothing.

So this doesn't look like a setup that can be fully secure.

Could even be completely fake and just to dissuade China from invading.

Stuxnet would like to have a word

That's what you have to do of you don't want the invaders to get the tech. If you brick the processors they still have the machines. I'm not sure what the secret sauce is in this case, but china has a reputation of reverse engineering things in spite of foreign laws. The best way to keep it from happening is to make sure they get no part of it.

So long as it’s fully independent and disconnected from existing digital infrastructure it should be safer.

It's a puzzle, because anything with too many safety features can be easily disarmed. But anything with too few can be prematurely detonated.

Imagine what happens to the Taiwanese economy if there's a Chinese feint or false alarm and the facility bricks itself. A massive economic downturn would not work to the benefit of an island so heavily reliant on foreign trade.

disconnected from existing digital infrastructure

Oh come on.... this isn't just a scrap metal press.