Without going off topic, you are right that Charles, Camilla, William, Kate and Sophie will take part of the pre-recorded Commonwealth Service programon BBC One.
https://www.westminster-abbey.org/abbey-news/a-celebration-for-commonwealth-day
As for stories that the Royal family try to overshadow the Sussexes' Oprah interview for moving a day forward (from 8th to 7th March), it's very ludicrous. It did not help that some staunch Sussex supporters ("Sugars") tried to spread rumours and conspiracy theories. It's almost as if they don't know about the service or even the Commonwealth.
Lainey Lui from Lainey Gossip also perpetuated this "coincident/conspiracy" by throwing the Royal Family under bus in order to make Harry & Meghan look good. What's even worse is that Lainey kept bringing Meghan's race into it and how the "pale, male and stale" royal family did not support her, as well as the Royal Family not being representative of the Commonwealth.
https://www.laineygossip.com/britis...ce-harry-meghan-markles-oprah-interview/68097
I am an ethnic minority in Australia and I find it very nauseating that Lainey Lui is dragging race and identity politics into every arguments just to appear virtuous. It's not Meghan's race that lead the Sussexes lose their royal patronages, it's because they are no longer full-time working royals, representing The Queen and doing public services in The United Kingdom.
Perhaps the news that the BBC not to broadcast Harry and Meghan's interview with Oprah could be the factor of the "overshadowing" stories (i.e. The Beeb does not want both of these programs on the same day)