We just had a scheduled banned and restricted announcement, and it was different than I expected.
First we have the unrestriction of Ponder in Vintage. Vintage has tried to regulate power levels in the past, but recently there have been so many supplementary products with pushed power levels that it's hard to keep cards like Ponder restricted.
The big change we see is the banning of Violent Outburst. There's been some criticism of this banning, but most people agree it's a necessary change. Violent Outburst was the only instant-speed-cascade effect for decks like Rhinos and Living End. The worst part is the deck could protect its combo with Force of Negation for 0 mana by using it on the opponent's turn.
I haven't played much with Living End, but having the ability to use your combo to disrupt other creature combo decks, like killing a Primeval Titan or a Yawgmoth at instant speed, is a problematic play pattern.
Ultimately, Modern is a busted format with more going on than just this cascade stuff, so I can't be confident this will make the format any better. It may slightly change the dynamic, but we still have decks like Yawgmoth and Amulet Titan that are in the running for being dominant.
My biggest takeaway from this announcement was not what was there but what wasn't there.
Pioneer had no changes to the format. While I haven't played Pioneer in a while, I have watched it a lot, including this past Pro Tour, and the format looked more fun and robust than in the past.
However, Phoenix was the most played deck going into the Pro Tour, and the players knew that would be the case, yet it still finished with a nearly 60% win percentage. It's exceptionally rare for a deck that is the most played to have that high of a win rate because the Pro Tour players often know what the most-played deck will be and choose their decks with that knowledge, yet Phoenix still managed to crush the Pro Tour.
If we saw Seth Manfield and Team CFB bring Phoenix to the event rather than Vampires and we had no new deck to talk about and distract us, there may be many more voices pushing for a banning in Pioneer.
That said, what exactly should be banned from Pioneer to weaken Phoenix? I'm less confident in that. Most people say it's time for Treasure Cruise to kick the bucket, but Cruise is a fun card for the format that people enjoy casting. With checks and balances, such as Fetches being banned in Pioneer, you can look in another direction.
Banning Cruise is functionally the same as banning Arclight Phoenix. The deck simply won't exist. Phoenix can't use Dig Through Time because mana efficiency is important in that deck, and Dig will still be available for other decks and is often the preferred card for other archetypes.
Cruise also gets hurt by the counterplay to Phoenix from cards like Rest in Peace and Leyline of the Void. There are some approaches to weaken the Phoenix deck, such as banning a cantrip like Consider, which they've done in the past to weaken decks like Storm in Modern and the aforementioned restriction of Ponder in Vintage, but you could also do something crazy like ban Lightning Axe to make the deck weaker against creature decks and to cards like Vein Ripper and Sheoldred.
Let's remember it wasn't too long ago that Phoenix was only an average deck in the format. The deck has gotten two new cards, Picklock Prankster and Sleight of Hand. If those weren't printed, the deck's power level may have remained where it needed to be. Phoenix is a tight deck, and the absence of any of its pieces outside of Cruise and Phoenix will weaken, but not break, the deck. You can hit those if they want to destroy the deck, and if not, then it's the dealer's choice.
We can wait a bit to see how Pioneer shakes out. Let the Metagame react, and if action needs to be taken do it before the next major Pioneer event like a Regional Championship or Pro Tour. It's good to not immediately ban something that overperforms. Keep in mind this is a game that people like to play. When a deck is the best, people will play and learn that deck. Giving the metagame time to adapt allows players to find answers and gives them space to play a deck they just acquired after watching it at the Pro Tour.
Some people like playing overpowered decks, and some like to fight against them. There was no outcry for a banning of Phoenix before the Pro Tour, so let it sit and see how it settles.
If nothing can compete, then it's time to reconsider things. We should let it play out right now and think about what cards could be banned to make the deck the appropriate power level. Phoenix is a popular deck and it’s easy to adjust, rather than nuke, the deck.
Ultimately, I liked how they handled this banned and restricted announcement. They did an excellent job pulling the trigger in Modern but keeping Pioneer untouched. I got excited about a Constructed format for the first time in a while when I watched Pioneer at the Pro Tour. To me, that is a big enough sign to let things be for a bit.