Churches that do not recognise divorce do not have a category of person who is a 'divorcee'.
Once you are married you remain married, in the eyes of that church, until your spouse dies. You might separate, you might have a civil divorce, but the marriage remains in the eyes of the church.
So, to a church with that attitude, Charles was never a divorcee, he was married to Diana even after their civil divorce, and not free to marry again. After her death he was, obviously, no longer married and therefore free to marry again.
They would also say that Camilla is still married to APB, not that she is a 'divorcee'
But in any case, the CofE does recognise divorce these days, so it is splitting hairs...