It’s a desperately sad situation, now that they have children. Ideally, Meghan and Harry will remain happily married, raise their children successfully in California, and all this brouhaha involving the RF will fade away. The children will grow up to have identities outside of the RF, and west their titles (that their parents have foisted on them) lightly or not at all. You hope for a happy, quiet, even-keeled life for them.
That’s sad for Charles and William though. More for Charles, as the father. Not so painful as a sibling.
They’ve proven themselves untrustworthy and disloyal, and unable to keep their mouths shut. That’s not good as members of any family, let alone a public one, and certainly not when your family = your life’s work (Charles and William). Publicly criticising you = publicly criticising your vocation, all that you’ve sacrificed a quiet life for, the choices you’ve made for your children (talking about George et al), and the livelihoods of lots and lots of people who rely on the RF. There would come a point where it becomes a bigger political (as in, Parliament) issue also.
Given all that’s at stake with a renegade couple like Harry and Meghan, no, I don’t think they’d be welcome. If we ever see either of them again, it would be after an about-turn to beat all about-turns. And, many years down the line.
Most realistically, I think it’ll be a lifetime of sniping and griping from the sidelines. Harry is a literal prince in self-imposed exile. Meghan will forever be hounded by the press. It will be ugly, for a long time. Just staying stable would be tremendously hard work for them.