A very muddled article from the Mirror - what a surprise!
As others have noted, there’s a big different between the 56 members of the Commonwealth, which appears to be thriving as an organisation (though the Commonwealth games are not 😀) and those remaining countries that have the UK Royal Family as their Head of State.
The latter countries will also most certainly transition to become independent countries in due course - I can’t imagine why anyone would think they wouldn’t? And I also can’t imagine that the Royal Family would think it appropriate to try and stop that. As Prince William recently said, the royal family has, and will continue to, stand by any country that wishes to part ways with the British monarchy.
One of the most notable elements of Elizabeth’s long reign was the peaceful transition of the majority of the former Empire to independent nations. This is not something that all the former colonial powers have achieved. I fully imagine that we will see the Prince of Wales attending peaceful ceremonies to mark the transition from former realm to independent country, just as his father and grandmother so often have done. None of these countries are suggesting leaving the Commonwealth, however. It’s a separate issue.