I posted this on another thread, but it’s far more fitting here - I don’t know why there’s been so much speculation over the DofE title.
They tend not to do many big things, other than securing the direct line, in a short space of time after the death of the monarch.
He was never going to make Edward DofE right away. It was always going to be on an occasion after a decent amount of time had passed.
It is, however, interesting that it’s a lifetime title. So won’t pass to James and therefore, unlikely the Kent and Gloucester titles, won’t become a non royal dukedom. I think that will become more common with titles going forward and is certainly more fitting with how E & S have brought their children up.