[Update #2]: Shadow Over Innistrad Remastered is coming on March 21, 2023, and the Alchemy: Phyrexia mini-set on February 28.
[Update]: The Alchemy: Dominaria mini-expansion has now arrived with 30 new cards and Historic 'unrebalances.'
In celebration of Magic: The Gathering's 30th anniversary, MTG Arena will be remastering the Shadows over Innistrad and Eldritch Moon sets. While the exact details have not been revealed just yet, you can expect Shadows over Innistrad Remastered to arrive by the first half of 2023.
Much like the previously remastered Amonkhet and Kaladesh, Shadows over Innistrad Remastered will bring with it the full suite of limited game modes, a variety of cosmetics, as well as an assortment of fan-favorite cards people have been clamoring for years. These will likely include Emrakul, the Promised End, Anguished Unmaking, Archangel Avacyn, Thing in the ice, and the list goes on for a while.
The good news doesn't end there, however, as MTG Arena will also be releasing Explorer Anthology 2 at some point later this year. Once again there are no details on what the inclusions will be, but given the homogeneous state of the Explorer metagame I'm hoping for powerful cards like Nykthos, Shrine to Nyx to give currently underpowered decks the push they need to become truly competitive.
Whatever the case may be, I'll make sure to let you know once more information becomes available. Until then, you might be interested to hear that Alchemy: Dominaria will be launching on October 6th alongside a chunky balance update and plenty of fancy Unfinity cosmetics! You can read more about these additions over at the MTG website.
Enjoy!