Isn't autoplay about always revealing Moat whether it's actually blocking an Attack or not? What Dippy was requesting was a change so that Moat is never revealed when the Attack actually has no effect. It would only apply to Moat, as that's the only Reaction that does nothing when the Attack has no effect. Of course such a feature would need to check a number of things for each kind of attack:
* If it's a junker: Is the junk pile(s) empty?
* If it attacks players with at least x cards in hand: Do you have x cards? (I'm not sure if this is in effect already)
* If it gets cards from decks: Do you have cards in your deck? (This one is so rare that it's probably not worth it.)
* If it's "take a token": Do you already have the token?
There's a number of complications though. For instance Swamp Hag has to always be Moated, because somebody could return Curses to the supply before it's your turn.
Also, some Attacks do several things (like Followers) so then each of the things have to be nothing.
In conclusion, this sounds way more complicated than it's probably worth considering all the much more important stuff that's missing and bugs that need fixing.