With all due respect PP stepped down 3 years ago so there is no official role to step into, it's already been done. That visit was probably when he was told that there was no further treatment and to prepare to bring PP home to pass away there.Prince Philip used his final weeks to prepare son Charles for taking on his role
Royal sources disclosed Charles had visited him at the King Edward VII’s Hospital at the end of February and they had “full and frank” and "heartfelt" discussionwww.mirror.co.uk
This explains why Prince Charles was so visibly upset after the hospital visit.