Especially if they're lawful orders, like this.

It’s a pointless question. If he answers no truthfully he gets fired. If he lies and says ‘yes’ to keep his job we get undue anxiety when there already enough of that going around from memes and trade wars.

This is almost certainly why he won't answer the question either way. If he says that he wouldn't, Trump would just fire him and replace him with someone that says they would privately, away from any public scrutiny at all.

It would be a net negative for everyone other than fascists.