I would with DD, apart from that, no thanks.
I've worked in the USA for a couple of short term contracts (NE USA). Then in South Africa for a year that turned into over a decade!
It is difficult to move to another country and culture. You have to be pretty resilient and accept that customs and understood ways of interacting will be very different - it will be a few years before you can start to gauge whether someone is being deliberately unfriendly or you are breaking the usual social rules without meaning to. Even after 10 years in SA I was never completely sure, but by then I had some good friends who I could talk to and they could explain.
Also, however welcoming people want to be, you are fitting in with their established lives. They have their family, friends and routines. It takes time to create genuine friendships and your own circle of people you choose to be with - several years is realistic. Until then you have to be quite emotionally self-sufficient - not because anyone is being mean, but just because you have chosen to leave all your friends and routines behind and start again, and it is not something anyone can do for you.
Moving back to the UK meant doing some of it in reverse, in that all my friends had moved on with their lives, and often moved geographically. On the other hand, I was coming back to my culture of origin, so making friends and fitting in was a lot easier than the other way round.
I get the feeling Meghan (and Harry) had unrealistic expectations, and didn't take enough time to allow reality and their shared assumptions to collide (as they inevitably do when you make a huge change), and then work through what that means and make a more informed decision based on reality.