I think Wills is now fully aware of the optics and just how important they are to the dastardly duo. The elder Royals are not so well versed in how these things play out. They've only ever really had the Press to deal with regarding how a situation looks, but these days with cammeras and CCTV everywhere things are more of a minefield. Wills will be most aware and I hope he takes the opportunity to freeze hazza out. He halfway did it at the commonweath service by barely saying hello and then sitting stone faced refusing any chit chat.The difference between now and Diana's funeral though is that there is a known rift between the brothers, due to Harry trash talking his entire family. It may just be protocol, but I also think the decision to have them separated could be because William didn't want to have to walk next to Harry. And I don't blame him for that.
The only problem is that Brenda may have dictated a united front ( public hugs/handshakes)be shown for the cameras. I feel so sorry for him stuck in this position. We all know he wants to kick hazza in the area where his bollox used to be, but he's gonna have to be polite at the very least.
But he knows any tiny gesture will be spun into a " See! Wills is fine with H. Such a fuss over nothing" or a "SEE! I told you they were nasty bastards, thank heavens heavily pregnant Meggy weggy avoided such shocking abuse".