I just had a HORRIBLE thought.
Okay, we know that Ebenezer is the Blackstaff.
We know that the Blackstaff is an actual thing.
When we first saw it, it "appeared" out of nowhere during the battle of Chicken Pizza.
Further, we know that Ebenezer has a hat, similar to the one that appears on the covers of the books on Harry.
What if, like the sorting Hat, the Blackstaff LIVES in the hat, and that is how Harry will inherit it, and from then on Harry will have to wear a hat?