Unlikely based on what? Exactly? I mean the past UAs were unbranded and left out obviously identifying content before. What evidence do you have they were planning on doing that any differently, before the leak?
UA01 "Eberron", UA27 "The Artificer, Take 2", UA53 "Races of Eberron", UA54 "Races of Ravnica", UA49 "Preview - Duergar", UA55 "Dragonmarks", UA56 "Magic Items of Eberron", UA59 "The Artificer Revisited", UA60 "The Artificer Returns."
As opposed to the following UA that were scrubbed:
UA04 "Waterborn Adventures", UA11 "That Old Black Magic", UA44 "Eladrin and Gith", UA45 "Fiendish Options", UA46 "Elf Subraces", UA50 "Order Domain", UA51 "Centaurs and Minotaurs', UA57 "Of Ships and the Sea", UA63 "Bard and Paladin", UA75 "2020 Subclasses, Part 4", UA76 "2020 Subclasses, Part 5", UA77 "Gothic Lineages", UA78 "Folk of the Feywild", and UA79 "Draconic Options". That's just 14 articles.
Tomorrows UA will be article No. 80, and between the two groups of articles we're still at only like 30% of UA articles. The vast majority of UA articles are neither clearly identifying nor scrubbed; they're generalized options that either never made it into anything or whose ultimate destination was a big book of options as opposed to a themed setting book.
The likelihood I stated was because they've had a number of cases above that they didn't scrub of setting content and we knew they were announcing something. If they were announcing Strixhaven next week, I highly doubt that they would have scrubbed the Strixhaven UA of details; they would have run it like "Races of Ravnica." But I guess they might have ONLY planned to announced the Feywild Adventure, in which case I would they could have very well scrubbed Strixhaven. So perhaps it's a coin toss?
EDIT:
With Ravnica, they let us know it was coming so they could put out a UA that clearly had MtG IP for races. I would wager they were waiting till the last moment to do something similar here.
You said this more elegantly and faster than I was able to type my analytical and long-winded defense of my use of "unlikely."
