Become a means of funding GOP candidates separate from Trump and the RNC.
I imagine a lot of GOP donors wish to contribute to more moderate candidates and would do so if they could find a vehicle.
And since Nikki Haley already has more money than the RNC at the moment, why not make her PAC that vehicle?
It would make her a major power player behind the scenes. And she could move the GOP away from its corrupt core.
She might even move it out of the GOP later, when Cheney starts a new party of the right after the election.