I call BS on having the Middletons fill in for royal duties. We might see them accompanying them though- especially when the younglings are present.
In comparison I do prefer the blue dress- but the belt is somewhat wrong. I get why she updated the white dress- the flowery shoulder looks really dated but the new sash doesn’t really work in white or maybe the black gloves just made it look like that. If I see white or very pale dresses like this I do immediately wish for a Grecian goddess touch. Messy updo and all. The brighter colour definitely was a good choice with the open hair.
In general I think a one shoulder is a beautiful look on most people.
Agree with
@Eirawen : an abdication would be a completely different situation than 1936. And while I think that an abdication due to not getting your way would be highly frowned upon (in the family, the institution and the public), abdicating because you can’t fill the role properly for health reasons would be a different thing. Even though they could also just update the regency act to make a regency easier AND find a new way to organise the reign of a minor. I could see Anne or Edward or even Kate filling in as Regent, highly supported by the Privy Council.