Maybe she wants the Royal Sussex brand back. She and Harry started that after Queen Elizabeth made them Duke and Duchess of Sussex (and they’re referred to as the Sussexes), but they gave up the branding when they stepped back from royal duties.
Meghan thought Royal Sussex branding would make them a lot of money.
For good reason, Elizabeth forbade the “Royal Sussex” lifestyle and goods branding scheme. In addition to basically being a celebrity endorsement grift, it would have made Meghan and “the Sussexes” the commercial face of the British monarchy.
Since there is no royalty in America, it seems to me that they should go by Harry and Meghan Mountbatten-Windsor.