He will stand or fall by his royal connection in the final analysis. He has lost so much already.
But he still has much to lose. It's still possible for him to return (not that he wants to): in his mind, he still - STILL - thinks daddy and the family and the country would take him back if he were on his uppers. I don't underestimate his entitlement. Also, it's true: there's no way that Prince Harry would ever be left on his uppers. At worst, he will be "managed" like Andrew is being managed, or Edward Windsor was managed. He'll never lose it all, but he still has a lot more to go before he gets even close. Not so for Meghan. Her worst case scenario, as the children's mother, is a modest house with a modest stipend in California somewhere. That said, Meghan will always be fine. She can more than look after herself. She's a hustler par excellence.
I don’t agree at all that the Palace have semi control over them while they are on the website, they have no control at all, we have seen it in black and white played out for the world to see
It could be so, so much worse. A throwaway comment about racism, walked back and attributed to third party: look at the damage that did to the head of the Coommonwealth, and how much extra work it will have created. A throwaway comment about lip gloss and not being a hugger: look how much that revealed to the public about Catherine's carefully curated public image. All they need to say is that (eg) Catherine likes a martini or 3 every evening; Charlotte is a spoilt brat/Mean Girl; William's temper resulted in xyz plausible consequence on such and such date. That's just tittle tattle that would be a pain in the neck to manage. But there would be things there that could totally pull the rug out from under the future King and Queen's in terms of the actual work they do: disclosures about how finances actually work, a comment Catherine once made about how boring and exhausting such and such charity visit was, dealings relating to her family. I mean the pair are managed and curated and supported and polished to an unbelievable level, one that probably nobody else in the country experiences.
Ex-communicating Harry and Meghan won't stop any of this. In fact, it would give them no reason NOT to do it, and the damage would occur anyway. It's basic, basic strategy. We all have to live with unpalatable people in our lives at times, if only because the alternative would be worse. This is one such instance, but with bigger factors at play. Nobody cares if Harry and Meghan throw their toys out the pram. That wouldn't harm anyone. It's the throwing of missiles that would hurt.