Capital wants clear and stable rules. If a king can provide those, then Capital likes the king. I'm not sure clarity and stability of rules is a property of the upcoming american monarchy.
When such an opportunity appears, capital jumps at it. It did it in Russia in the 90s and it's doing it in the US right now.
And if anything history often shows that capital doesn't want a king while the people demand it.
This is one of the areas where a popular leftist mantra tends to be right in its conclusion (“Capital will always side with fascism”)—and this works for a wide variety of authoritarianisms that don’t overtly seek the utter destruction of private capital, not just fascism in the narrow sense—but exactly backwards in its rationale (“because fascism does not threaten capital”, when in fact the reason is because fascism does threaten capital, but does so both less and less immediately for capital that cooperates with it than capital that resists.)