Huang has been very (relatively) vocal against the administration that preventing Chinese organizations from having access to Nvidia chips will 1) not really work, because they'll get them anyways, and 2) lead to a surge in availability/popularity (and inter-operability) with Nvidia's functionality.

Whether you agree with his outlook or not, he was vocally against the current administrations' priorities/opinions. Undermining his opinions as "well he was convinced of that by a spy", or even just removing him from the position where he can have influence, helps the current US administration (which, notably, is not necessarily the same thing as helping the US)

He didn't say remove, he said undermine, i.e. put him in a position of weakness. Jensen holds a lot of power.

Same way that starting a trade war and destabilizing the global economy helps the US.