Ok, so this is what we DO know.
They announced this on Instagram. There is some evidence in the media that this was done without prior consultation with Her Majesty or the Palace. The Palace have issued a carefully worded statement which isn't exactly overly positive. No-one really knows if they will renounce HRH status, who will pay for their security or what is meant by "Financial Independence". They trademarked the name "Sussex Royal" in 2019. Have I got everything?
This is what I THINK the plan is. To live mainly in the US/Canada as private individuals, possibly starting a charity and possibly trying to leverage the "Sussex Royal" trademark to earn some kind of an income. We know Harry has never worked outside the Services. Meghan did earn good money as an actress, but she is a Mother now and that would be difficult for anyone.
Now some opinion. They WILL attract a lot of criticism for avoiding protocol and not involving the Queen or letting her have some advance notice at least. Whatever your position regarding the Royals, when the Matriarch of the family is the last to know, it always ends badly, whether you are talking the Crown or Peaky Blinders.
Yes, comparisons with Edward and Wallace Simpson will abound due to Wallace being American and universally disliked. But there are SOME similarities. For example not a lot of people know that Edward tried to make overtures to various American companies/Universities/individuals, possibly with the intention of giving himself something to do and earning some dosh. But he was rebuffed at every turn. And the reason? He wasn't Royal anymore.
I THINK there is an intention here to somehow leverage the Royal connection which they feel they can get away with as private individuals. And hope this will earn them some cash. But the fact is, once you renounce your Royal status you are no longer a Royal and no-one really wants an ex Royal because it's a bit sad. Ask Sarah Ferguson, who had to resort to ghost written children's books and being patron of a company promoting weight loss but who has largely vanished into the ether. So that makes it quite difficult to earn wads of cash from trademarking something like "Sussex Royal". I think they will probably make some dosh for charity and Invictus was a good charity and I hope they continue with that. But short of opening supermarkets I don't hold out much hope for their financial future. Maybe they could go on I'm a Celeb. That's always been good for reviving flagging careers.
My advice would be to shove off to the USA, have a few more kids and retire from public life entirely. They are not exactly going to starve.