When you have a president for life, they can play the long game. Congress running for election every 2 years prevents people from taking any position that could affect them 12 months later.
The People's Republic has always viewed Taiwan as...
They would have no reason to do so.
Not supporting existing customers is very different than not selling directly to new customers. There isn't a foolproof way to implement this that wouldn't risk affecting service to drones outside the US...