A General Note (Non-Functional but Yeah, Read On)
Many old cards were printed with words that worked off a number of rulings. As time went on, they were reworded to fit into the game's current rules structure. Sometimes that still takes a bit of hand-waving and rulings, and generally that's okay. This General specifically was a bit of a jar of worms, since "switch" was being used in a way that wasn't well defined. So, using Sorrow's Path as precedent, we've updated the words. (You didn't think you'd read that sentence when you woke up this morning, did you?)
Say hello to General Jarkeld's new look! The intent of the new words is to match all the existing rulings and functionality—the rulings included that the creatures didn't "become blocked" again, that the switch had to be legal, and that both attackers must be blocked. At least, those are the rulings we found that we expect should be upheld. Who even knows how many contradictory rulings about this card are out there? For that reason, this change isn't functional, but having the answer to its functionality being clearer may change how you play it.
General Jarkeld was:
T: Switch the blocking creatures of two target attacking creatures. Activate this ability only during the declare blockers step.
T: Choose two target blocked attacking creatures. If each of those creatures could be blocked by all creatures that the other is blocked by, each creature that's blocking exactly one of those attacking creatures stops blocking it and is blocking the other attacking creature. Activate this ability only during the declare blockers step.
Could You Kudzu? (Functional)
As General Jarkeld reminded us, templating on very old cards was much more art than science. Take a look at Kudzu, for example. Not the Vinelasher one, the Aura. In all its printings, it says that after Kudzu swallows a land, Kudzu is not "discarded" (of course not, you can't discard things from the battlefield). Instead, the player "may place" Kudzu on another land.
The current wording for Kudzu makes this mandatory, which is a tough sell with that "may" in there. When an old card is played by a broad group of players, we may make exceptions for intent versus the words printed on the actual card (looking at you, Winter Orb), but we agreed that Kudzu doesn't fit the bill.
When enchanted land becomes tapped, destroy it. That land's controller attaches Kudzu to a land of their choice.
When enchanted land becomes tapped, destroy it. That land's controller may attach Kudzu to a land of their choice.
Civic Wayfinder (Non-Functional)
Civic Wayfinder's been doing an exceptional job at ushering people through the streets of Ravnica, so it's getting an exciting promotion! This promotion doesn't come with better pay or benefits. It doesn't have better hours. It probably just means more work for Civic Wayfinder. Civic Wayfinder has been promoted from a Warrior Druid to
Civic Wayfinder was:
Creature — Elf Warrior Druid
New type line:
Creature — Elf Druid Warrior
Palisade Giant (Non-Functional)
Gideon's Sacrifice in War of the Spark moved us. The card, not the story moment. We felt deeply that its words are the better way to express a prevention effect covering multiple things. We were so touched that we brought Palisade Giant in to make it as cool as this card. It's not a functional change, but it's bringing these two cards together under one template.
Palisade Giant was:
All damage that would be dealt to you or another permanent you control is dealt to Palisade Giant instead.
All damage that would be dealt to you and other permanents you control is dealt to Palisade Giant instead.
Ever-Watching Threshold (Non-Functional)
Ever-Watching Threshold comes up a little short of our threshold for ambiguity. It clearly triggers only once if I attack you and your planeswalker, but what if I attack two different planeswalkers you control? We decided to clear this up a little with no functional change: Ever-Watching Threshold triggers only once, no matter how many of your planeswalkers are being attacked.
Ever-Watching Threshold was:
Whenever an opponent attacks you and/or a planeswalker you control with one or more creatures, draw a card.
Whenever an opponent attacks, if they attacked you and/or a planeswalker you control, draw a card.
It Continues to Deal (Non-Functional)
Last but not least—actually, no, this might be a strong contender for least—21 cards have been updated to say "It deals" rather than "CARDNAME deals" when that's the first thing an activated ability does and the card's name was immediately referenced at the end of the activation cost. We changed a bunch of these back in Dominaria but expanded the criteria a little further with War of the Spark.
For example, Bloodfire Dwarf was:
R, Sacrifice Bloodfire Dwarf: It deals 1 damage to each creature without flying.