There are many, many profiles on WikiTree that would rate the title "unproven existence"; they are simply waiting for a little bit of attention and research and adding the sources that can verify not only that the person lived, but that the person had parents, spouses and children.
We have commented time and again that we wished there was a better title than "Disproven Existence", and we acknowledge that technically, one cannot prove a negative. But we have not come up with a better word. Disproven Existence goes beyond what is suggested by "unproven existence". It states that we have made an effort to prove that this person ever existed and have found no evidence. Therefore we are quarantining the profile. It is not connected to other profiles. It will not show up in any table of ancestors. Disproven Existence is a positive step to protect WikiTree users from imagining that this person ever lived. That is why we don't take it lightly and we require a week's notification. It goes beyond absence of proof. It makes a definitive statement that in this case, we do think that the Maud d'Avranches described in the profile never existed.
But rather than discouraging research, the designation is a challenge. Some of us embody that challenge in our disproven existence notices. "Prove us wrong! Find the documentation! You'll be a hero!"
This is one of many reasons we don't even think of deleting disproven existence profiles. They are sitting there waiting for us to be proved wrong, and when a hero steps up to accomplish that, it requires only a couple of key strokes and connections to restore the profile to active status.