Having a spouse with a US passport allows for extensions in in securing a permanent resident alien status with a green card. His status appears to be confidential but speculation is that he has until this summer to secure a green card.
No Title of Nobility shall be granted by the United States: And no Person holding any Office of Profit or Trust under them, shall, without the Consent of the Congress, accept of any present, Emolument, Office, or Title, of any kind whatever, from any King, Prince, or foreign State.
Interestingly, though, it worked the other way for Conrad Black, who was offered the title of The Baron Black of Crossharbour in 2001. The Prime Minister of Canada at the time, Jean Chretien, objected to the title, citing the Nickle Resolution of 1919 disallowing the practice of bestowing titles of British nobility on Canadian citizens. In response, Black renounced his Canadian citizenship. Later, this made his eligibility to return to Canada questionable after his criminal conviction in the US. He was eventually re-admitted, but his long-term status is still uncertain, AFAIK.
Meghan doesn’t have a title of nobility; Harry does. In British peerage law, the title exists only once, and is assigned to an individual titleholder - which is Harry, in the case of the title of Duke of Sussex. Meghan, being the wife of a Duke, has the courtesy title of Duchess, but the peerage is Harry’s.
WAG - his job is to be the famous face of the brand in order to attract punters*, investors and publicity. Lots of being at events and dinners and shaking a lot of hands, plus mentioning the company name in public at every opportunity.
I assume the US has similar employment laws to the UK, where companies can ‘sponsor’ the employment of a foreign national if they have unique skills/experience - there’s certainly an argument to be made that you’d be hard pushed to find a better person to fulfil the role of ‘Chief Impact Officer’.
My sister in law works for a major US business - originally in the UK, but now in the US. I assume the business sorts out her green card.