Don't worry about Harry he won't have changed much, he knows the score and is on friendly territory, save your concerns for Meghan.
She is a junior member of a very exclusive clan where every move, every gesture, every expression is scrutinized, she will make protocol mistakes, so let's hope those around her make allowances. It is not like being an actress where you are on screen for a few minutes at a time then relax and be yourself she has to live the role.
Of course materially she will want for nothing but we all know that money does not equal happiness it is up to Harry to give her love and confidence to make her happy, he knows all about the failings of his father and is very aware of his mothers tragedy.
Her resemblance to Wallis Simpson is unfortunate, that was a love match too, at least politics won't get in the way this time.