Do they actually have to work on creating these concepts or is that just PR talk? I can imagine Netflix 'buying' their name - as they did with the Obama's- and the couple approving a project suggested to them by Netflix and perhaps have some modest input. But I have a hard time imagining them, the Obama's or most other celebrities actually coming up with concepts themselves. Programme making is a profession.
I mean, you're sort of right with the top half. They're producers, and while producers can have some sort of impact and etc when creating a show they mostly fund the show. And I think it just depends on the project.
Heart of Invictus? I'm pretty sure was apart of the direction.
Archetypes (not a tv show but a project from her), she was apart of it.
Live to Lead - I'm pretty sure it was already in production and they helped fund the rest of it.
Pearl - When Netflix cut animation, some of the people working on the project talked about it twitter (x) and said that they were super happy to be working on it, it was bummer and Meghan had some great ideas.
So I think it can very depending on the project and how much they're connected to it. Like, Meghan wants more rom-coms and wants to make rom-coms so I'm guessing, she would be a bit more active in that area. If it was something to do with sports, I expect Harry would be more active but overall, it's a production company and that means funding the projects that come their way or idea's for shows/film.
As for the rest, it is a profession but it doesn't mean someone isn't creative enough to come up with concepts. And no one in a profession does it on their own. There is the snow-runner, producers, exc producers, a show can more than one writer and etc. Just like writing a book, most book-righters go through publishers. Yes, the author wrote the book but they had an editor to help guide and etc during the process.
The Sussex's or the Obama's or any other celebrity, can come up with concepts. It's more about having a team that can make those concepts come to life.
So I think the Sussex's could do a mix but they're producers as of right now, which means funding projects like you said. It could be that Netflix comes to them with a project or they're looking at scripts and selecting that project.