It’s purely political and diplomatic - a member of the Royal Family visiting the Falklands at the moment in any capacity could upset the Argentinians and make negotiations more difficult. The question is how much of a concern this really is right now.
The Argentinians have the Falklands Islands set to a religious level. If you look into it, the hysteria is actually frightening. You have to ask though, if they honestly think the Islands are theirs why don’t they fight for it. I am sure the US and UK would fight anyone if their own nation was supposedly invaded.
With oil drilling starting in the area it’s best to keep them quietish. It saves any petulance.
What is there to negotiate? The Falklands are British territory...end of story.