I've got no plans to delete it. So what cards do you think are going to be meta altering cards?
I mean we don't know the whole set as of yet, but so far
the strongest contenders for new cards, as far as I can tell:
Flutter Mane as a Lost Box ability stopper that's synergistic with Ancient Paradox decks. We need to find out if Escape Rope gets reprinted.
Order Box, Eri, Heroic Cape and Hand Trimmer new cards for Control. We need to find out just how big a loss Echoing Horn is, and if Heroic Cape is worth running over Prime Catcher depending on control's wincon. I think it will be Prime Catcher that comes out on top.
Possibly Hand Trimmer as a meta call depending on need to cull hand size of opponents mid-game.
Friendship Poffin (Buddy Poffin, whatever it gets named) in virtually every evolution deck, especially since VIP Pass is rotating. Lost Zone will more than likely test it too for Comfey, Manaphy, and Jirachi. This is the easiest non-Ace Spec card to call being useful.
Emergency Board as a generic -1 retreat tool will pop up at some point.
Prime Catcher as the main Ace Spec that matters to competition.
Code Maniac tested as a card that could be combined with any pokemon draw engine, Electric's energy engine, or used partially as an anti-Iono card.
Mist Energy as a possible tech for Charizard combating Giratina and Roaring Moon (Though, it already has a winning matchup on Roaring Moon). Not every hand of those is gonna be able to spawn a Temple of Sinnoh, and players will probably at least think about this card as a 60th card in the deck depending on if Tina and Roaring Moon hold up into next format.
There are other cards being speculated from this reveal set, like Relicanth as a card for past evo attacks, Dudunsparce as a pivoting alternative to Bibarel, or some folks doubling down on the new baby Roaring Moon. I am way more comfortable speculating the previous cards since they seem a lot more clean-cut on which decks they get involved in, and it's moreso on whether those decks are good.
For the remaining 4 Ace Specs we know of, I don't think any of those are gonna play out that well.
I am highly doubtful
Drum of Awakening is worth it for any Ancient Paradox deck that isn't focusing on Baby Koraidon, since it means you are giving up Prime Catcher. At least with Koraidon you are aiming to put as many Ancient pokemon in play, but Roaring Moon clearly doesn't want a draw-2 for an Ace Spec as an example.
With how unbalanced Stage 2 attacker design is right now,
Neo Upper Energy probably should have been printed as a non-Ace Spec (in perspective of Standard; maybe Expanded breaks this?). It will only show up in decks desperate enough to run it to function, or stall decks that somehow have a plan for it and need it specifically over Prime Catcher or Heroic Cape, which I don't think that deck exists.
Master Ball is straight up not worth it. No one pokemon is gonna justify running that, especially when we have Ultra Ball in the format. It isn't ever worth it over it over Prime Catcher. Comp Search might be a slightly different story when that can search stuff like Poffin, Generator, and Colress's Experiment that have a lot of importance on a deck's setup.
There are people putting thought and hype on
Reboot Pod, but without other Future support I don't see this being enough a push to make Future Para-box a competitive deck. Some folks are claiming Miraidon as an energy starter for its attack will be enough to push the deck that way, but I honestly doubt it. I think we need to wait for further support on this one.
I would have to assume the final Ace Spec is a tool as Wild Force 66/71, but who knows? Let's just wait until the last Ace Spec gets announced.
As far as new decks go, there's much to figure out from new contenders and
nothing feels like a surefire good deck yet and there's plenty of work to be done to figure out what's even good. Raging Bolt has a crisis on a supporting engine between sustaining damage and hitting enough damage early. Gouging Fire has a damage problem with Charizard that people will try to patch with a tech grass attacker like Iron Leaves (which introduces inconsistency), Baby Roaring Moon likely doesn't fix Roaring Moon ex, and honestly needs to find a way to be played effectively without 2-prize pokemon in play. Future Box I am rather unconfident in without more support. Incinceroar is good on paper for efficiency, but has matchup problems and is eclipsed by Charizard ex.
Nothing's really figured out yet for new decks, and there's still packspace to go.