A lot of teams decided to play it safe for the Standard portion of Pro Tour 25th Anniversary, but if we take a look at the decklists, we can find some interesting archetypes. One of those is the Green-White Cats deck that was played by Dirk Crasto.
We've seen Green-White Cats decks even before Core Set 2019 showed up, but those were mostly green-white decks that happened to have Cats in them. This is a legitimate Cats tribal deck, where every creature is a Cat and you have Unclaimed Territory, Radiant Destiny, and many lords.
All in all, this deck should play similarly to any dedicated tribal deck we've had before, such as Merfolk, Zombies, or Humans. It's a critical-mass deck; your creatures are weak by themselves, but grow exponentially the more of them you have.
The pros of Cats as opposed to other tribal decks (other than the fact that Cats are cool) is that the pump effects scale very well. A lot of your creatures have lifelink, which means you're getting more mileage out of pumping them, and one of them even has double strike. On top of that, Regal Caracal, Pride Sovereign, and Leonin Warleader are all capable of making multiple Cat tokens, which really reward you for having those mass pump effects. You also have two creatures that can bring themselves back from the dead (Sacred Cat and Adorned Pouncer), which means you aren't just dead to mass removal.
The con is that you have almost no disruption. A deck like Modern Humans has Kitesail Freebooter and Meddling Mage, for example. Green-White Cats has none of that. You're kind of at the mercy of what your opponent is doing; your goal is that you each do your own thing, and then that yours ends up being better. And, even though you do have some recursion with the embalm and eternalize Cats, you don't have nearly as much as, say, Standard Zombies.
I like the list Dirk Crasto played, but I think there's one glaring omission: Appeal // Authority. This is a deck that can go very wide and also very big (with Pridemates, which grow constantly due to all your life gain triggers and lifelink), so it can get huge rewards from giving a creature trample. It also has double strikers, which are the best target for Appeal // Authority. I actually played against Dirk during the Pro Tour, and I was constantly terrified of Appeal // Authority. I was playing Mono-Blue Outcome, and relied on chump blocking big Pridemates with Thopter tokens over and over, which would not have been possible if it ever gained trample. On top of it all, the aftermath part lets you temporarily get rid of annoying blockers like Rekindling Phoenix or Torrential Gearhulk. It doesn't get rid of them forever, but you should be attacking for a large enough amount of damage that it won't matter.
I think Blossoming Defense is a good card, especially if you're trying to protect your lords, but Appeal // Authority is just too strong at what it does. You also can't play a million tricks though, as you need creatures for your deck to work, so I don't think you can play both. My inclination is to cut two Blossoming Defenses and two Thopter Arrests for four Appeal // Authority, and then just try to be the best aggro deck you can be.
Dirk Crasto's sideboard has one very interesting twist to it: three Banefires and a Mountain. This is his only red source in the deck, and it's relying completely on the fact that he will get hit by Settle the Wreckage (or Field of Ruin—but mostly Settle). This deck has a lot of creatures, so if you do get hit by Settle the Wreckage, you can cast some enormous Banefires.
That said, I don't think that's good enough, because it applies against literally only White-Blue Control. This sideboard plan doesn't work versus Grixis, Esper Control, Turbofog, or Mono-Blue Outcome. Your opponent has to have Settle the Wreckage, and they have to draw and cast it. If all those things happen, then it's not like you auto-win if you draw Banefire; you don't have any other burn, so you could still just lose anyway.
I think the biggest gains you can make on this list are in the sideboard, yet this color combination doesn't have many great options right now. Assuming I don't want to splash Banefire (which I don't), there just aren't great options for dealing with decks like Turbofog, White-Blue, or Grixis. I think that for the Teferi decks, Sorcerous Spyglass is your best bet. If you neutralize Teferi, you're not in as much of a rush to kill them, and then you can afford to play more conservatively around Settle the Wreckage and Fumigate, especially if you have Lifecrafter's Bestiary. For Grixis, the best option seems to be Shaper's Sanctuary, since they have a lot of spot removal. For Mono-Blue, you can play plenty of hate cards. I think the most effective is Manglehorn, but Cleansing Nova is also very good.
I'd try playing the deck like this: