Magic: The Gathering players got a peak behind the curtain when a data leak occurred online, revealing cards that would be available in two upcoming Secret Lair releases.
As revealed in several tweets credited to several prominent players and sources, it appears that Magic The Gathering Online revealed upcoming products that were not supposed to be seen yet, as the promotional cards had not yet been announced.
Furthermore, Secret Lair cards are highly sought after by both devoted players and collectors alike. In simplified terms, Secret Lair is a limited-run reprinting of cards from Magic The Gathering's history, dressed up with brand new artwork, foil variants, and updated text. These cards need to be ordered from a digital storefront handled by Wizards of the Coast. There is generally a short window for which to place your order, and it can take somewhere between six to ten weeks at most for the order to arrive based on demand. If you miss out on this narrow opportunity, the only way to get these versions of the cards is through secondhand means; most likely with a significant price markup.
As for the cards that were leaked, some have gotten considerable attention. One of these Secret Lair releases focuses on shocklands, which have generally only been released along with Ravnica sets, as well as being part of the Zendikar Expeditions. Interestingly, beyond the new art this printing also shows them taking place on other worlds, in the flavor text, with the Blood Crypt flavor text referencing Innistrad (Markov Manor is a clear callout to Sorin Markov), and Breeding Pool showing New Phyrexia, the plane formerly known as Mirrodin. Given that in the past they were always in the city-based Ravnica, this makes for quite the departure.
The second Secret Lair leak is for the Mystical Archives, which contain several infamous instants and sorceries, and ties in with Strixhaven. All of the cards in this Secret Lair have received the Mystical Archives showcase frame Other than the Emrakul featuring All is Dust, these cards are all ones that would have been a rough fit in Strixhaven as they run in allied colors while Strixhaven focuses on enemy colors. .This is also the first potential foil printing for Fractured Identity, and given that it was a limited print run in Commander 2017 may represent a not-insignificant increase in the number available. Fire Covenant also bears noticing as it is the first paper reprinting since its Ice Age release (it was released in an MTGO master set), and will be some players first time to acquire the card.
If any of these cards sound like just the thing to bling out your deck, then I guess your foresee was successful and you can plan to draw these two when Wizards of the Coast officially reveals them in the future.