The new patch brought a ton of new information about upcoming cards and there's even a hint of a new game mode! Let's get into it!
February
February is still set to be a Captain America: Brave New World season, but a couple of cards got major updates.
Redwing got a lot worse; he looked like the best card of the season but now looks like the worst. The previous dud, Cobra, now looks quite interesting in the face of the current and upcoming formats that are rife with generated cards. The rest of the cards are unchanged. Batroc isn't scheduled for a spotlight, so he'll either be part of an alternative acquisition method or be in another season.
March
The March season will be called Prehistoric Avengers and is based on the Avengers 1,000,000 BC storyline from the comics.
Agamotto will be the season pass card and he's another card that comes with a bunch of spells that are shuffled into your deck, more similar Thanos than Nico.
First up in spotlights is Eson, who looks like an incredibly fun deck-building puzzle and appears to have a new keyword: Legendary! I'm assuming Legendary will be a class of card of which you can only have one per deck. In other words, if they make Arishem legendary as well you wouldn't be able to put both Eson and Arishem in the same deck together. Hey Second Dinner, let's go ahead and make Arishem a legendary and then ban legendaries from Conquest mode!
Starbrand is a boost for big dudes decks, while Firehair’s ability leans into her roots as a Phoenix Force host.
Khonshu and Fan Fei also appear to have a new mechanic. They involve a very Magic: The Gathering style progression quest of moving from Waxing into Full (no sign of Waning). It appears the way to progress Khonshu’s journey is by destroying cards, while FanFei is possibly advanced via discard. We don't have signs of what the payoff for Fan Fei’s quest is yet, but Khonshu seems to give you an increased chance to transform into a Hulk. Of course, it's also possible there's something mixed up with the texts of these cards and Fan Fei’s text is meant for Khonshu. This feels quite likely since Fan Fei is the first Iron Fist, so it would make more sense for her to have move synergy. Also, I'm hoping whatever transformation Khonshu undergoes changes from Hulk to something more lore-accurate. We’ll keep you updated if the info in the game files changes/updates.
Ghost, The First Rider fits into the Prehistoric theme, but isn't currently scheduled for Spotlights. I doubt we'd get all three of these cards through Limited Time Modes or other systems, so I would expect at least one of them to be held back or put into another season.
April
We have confirmed that April will be a What if…? season! The only card name we currently have associated with the season is Dum Dum Duggan.
Speculating about other characters, Captain Carter and Kahhori feel almost definite along with at least one alternate version of a character we already have like T’Challa as Star-Lord for example. Maybe we'll get a mecha or zombie version of a character. Kingo would make a lot of sense since it would be a way to give us another Eternal, and Darcy Lewis appeared in a surprising number of episodes. Other possibilities that I think could attract the attention of the design team are Ying Nan, Byrdie, and Happy Hogan.

Sanctum Showdown
The datamines also revealed a new upcoming game mode called Sanctum Showdown! Could this mode be how we're getting the previously mentioned Brother Voodoo and Dormammu cards?

We don't have a lot to go on, but it looks like a totally unique mode that focuses on battling for locations across multiple turns. There will be fifteen turns and each turn one location will be selected as the one to be contested. Whoever wins that location that turn will be given points and one card from each player's side from that location gets shuffled back into their deck.
It seems like the primary strategy will revolve around when to go all-in to try to win a location and when to bide time by playing at other locations and holding your key pieces for the right time. Fifteen turns sounds like a lot, but I wouldn't worry about that too much; we don't know exactly what will be different from the base game functionality and there may be a way that keeps the pace furious and snappy.
We only have a small glimpse so far, but it feels like it could be a great mode that feels like a mix between a penalty shootout and a mind-game laden Chess match. After Conquest, Deadpool's Diner, and High Voltage it would be nice to get a mode that is sufficiently different from the base game that it has a chance to feel truly fresh.
High Value Bundles
This last bundle is quite pricey, but it's notable for having two series 5 cards. For someone who has neither card, this could be worth a look given that it also comes with 2 keys and 2400 Gold.
Wrap Up
The mechanics for the March cards seem unhinged and ridiculously fun, so I'm really looking forward to getting my hands in those. Here's hoping Agamotto’s spells are sweet. The new game mode intrigues me a lot more than the other modes we've been given which don't feel sufficiently different from ladder to really be worth the time. Hopefully Sanctum Showdown is fun and engaging. Hit the comments to let me know which Prehistoric Avengers you are most excited about and which What If…? characters you want to see added to the game!