I feel like not enough people talked about how the Izzet Discard Takesies Backsies was the exact same situation as Borborygmos, Arbor Elf, or "Combat".

Coming back to this well after the initial drama wound down because while thinking it over this was basically the exact same controversy we'd seen a rule change over 3 times in the past. For anyone who hasn't been around, three notable and highlighted matches were won off weird rules technicalities that cause a fundamental change to the rules of mtg.

A pithing needle was played naming borborygmos, to stop a deck that intended to win with a combo using borborygmos ENRAGED. Borborygmos was completely unplayable in the format, a legal card for a deck but one literally no one was playing. Everyone including the opponent fully understood the pithing needle to be on borborygmos enraged. Seeing no other way to win, the opponent went to a judge and basically said "since borborygmos is a legal target and he didn't explicitly say enraged, can I just use the card anyway" which was ruled in his favor and the sole reason he won. This lead to the rule that naming a card only requires you can communicate what card is supposed to be named and it's not about literally saying the name word for word. "The card that killed me last game" is a legal pithing needle target in the right circumstance.

Arbor Elf was a similar situation. The full land art version of arbor elf was being kept in the rest of the lands on the board. This lead to what would've been a lethal attack failing and losing the game because of a surprise arbor elf coming out to block from the lands. This caused the rules change that you are required to keep a clear separation between lands and non lands, and that you aren't allowed to meaningfully obscure any information by the placement of your cards. While I don't recall if this one was intentional or insidious like the other two in this post, it was still an important rules change from an incredibly dubious win.

Finally "combat" is probably the dumbest of the 4 I'm mentioning today. A player who was ESL had a start of combat trigger on his board. He said "combat" to move to combat and do his start of combat trigger. "Combat" was "official shorthand" that meant "skip straight to declare attackers." I'm not joking this is some of the dumbest shit imaginable. The opponent took advantage of this and called a judge saying he missed the trigger, and the judge agreed because of the "official shorthand". This lead to the rules change that you aren't allowed to skip phases they all still happen regardless of if you have actions to take on them, and nothing someone says should meaningfully be considered to be completely ignoring a phase.

Having stated all of these next to each other, let's look back at the take back from worlds. A player casts a spell, passes priority, and then on resolution decides he doesn't actually want to cast that spell anymore because he realized it's not good for him. The niche ruling on this is that it "didn't reveal any new information" so it's technically okay to take back the play.

The only argument that really held any water that I've heard towards this is that the opponent couldn't meaningfully respond or potentially respond at all with his decklist, and if decklists were open information then the priority pass couldn't actually reveal any new information about interaction since he would already know the opponent has no interaction. I've never really liked this argument because I feel it makes the ruling even more niche and unfair, making it an exclusive do over clause in hyper niche tournaments against a fringe number of decks.

And despite the similarities and niche situations it's relevant, this is the only time we didn't see a rules change about it. Because the thing is the current rules would probably ban me from doing this in any game for any reason unless I have full deck and side board knowledge of my opponent, or full hand knowledge at the very least. Even in pauper 1 tapped out mountain and a discard outlet could still be an instant speed surprise lava dart. Yeah tapped out in standard there might not be anything at the moment but for all we know a free instant is due any day now. Not to mention every other format where Phyrexian mana is legal, hell no lands on board can even be holding up a spell in every format other than standard with Gutshot or Mutagenic.

So I'm wondering why didn't this hyper niche rules technicality win see a rules change? What makes this situation different from these other three incredibly controversial moments in MTG. I'm not saying overturn the win but why are judges still allowed to allow take backs in this situation? I've played in locals that are tougher about take backs than the official worlds tournament was. Why ultimately is this the situation that stands alone?