You have my vote.
We ended up losing the Proving Grounds for Abyssal Arenas that clearly asked CCP to take care of them and invent more and more event Filamensts, which was obviously untenable.
Nothing warranted getting rid of the Proving Grounds, they asked for no dev attention and were their own little system (although I admit the bling needed to be reduced).
Now getting something that could be automated and that generates new kinds of Grounds would be nice, but more importantly, bring back something that had no need to be removed.