Have no idea what the King is planning, as he has not consulted me!
But FWIW, perhaps Charles will start as he means to go on with his ‘slimmed down’ monarchy.
By that, with a view to Christmas, maybe he will have a gathering at Windsor for some of the ‘lesser’ royals, and Christmas itself, at Sandringham still I assume, will not be such a large number.
Perhaps many family members have only been going for so long to keep the Queen happy. Like many of us, with growing families of our own, times change, and what was acceptable years ago may not be really how we want to spend Christmas.
A smaller gathering in their own homes, with grandchildren and close family members, might be the (longed for) way forward.
And perhaps Camilla wants to spend the actual day with her own family.