After the original announcement and availability at Amazon people spotted a second 12-figure box at Walmart, which we named Batch 1A quickly after. Instead of waiting for the second set to release at a later point we got a surprise update today: the second half of the set, Batch 1B, has just been released at Target!
Aside from the split of characters there are no other changes to the series. Even the codes on the packaging are exactly the same over all sets. More on that below.
This second half of the first batch (previously called waves) features Princess Celestia, Twilight Sparkle, Winona (black), Tank (blue), Angel, Gummy, Opalescence (black), a hippo and 4 unnamed unicorns.
Thanks to Victor & Samantha for the info and photos!

Earlier this week we found the first image of the brand new G4.5 blind bags set online, and just before the new year Walmart already released them in stores! (And Amazon now, too)
There's only one odd thing here: the set that was found on the shelves is a 12-pack, whereas the US normally gets a full 24-pack, just like the images we found earlier. Not only that, but the packaging only features English and French text, not Spanish as US releases usually have.
These 12-pack releases with two languages is commonly released in the UK, so it is possible that this set that hit the stores is a mix-up.
The figures included are the first set we posted in our previous post containing Tank, Winona, (brown) Angel, Opalescence, Lyra, Amethyst Star, unknown green pony, Gummy, Potion Nova, Cha Cha, a hippopotamus and Rarity.
While the Cutie Mark Crew confetti is gone, these new blind bags do come with another (potentially even messier) way of opening them: water! You can flip open the potion bottles, pour in some water, and after shaking them for a while the dust should dissolve and the pony will be revealed. Just make sure you close the potion bottle tight before shaking! (See photo and video of this below)
Update: First wave of Magical Potion Surprise is now on Amazon for just $2.99 each. Listing mentions 24 figures in contrast to the split box found in stores.

Thanks to SLPhotos for the photos & videos!