As I did for Sun & Moon Base Set, I chose not to model all secret rares having the same pull rate, even though assuming each one of the 15 cards printed 4 times on the sheet would yield 0.84 secret rares per box, not an outlandish number
While there are guidelines to keep in mind when deck building (no Game Changers in Exhibition or Core, no mass land denial through Upgraded, etc.), the bracket system is emphatically not just "put your deck into a calculator, get assigned a rank, and be ready to play." I deeply appreciate the tools that websites like Moxfield and Archidekt have put together to give you an overall estimate, and they've done some fantastic iteration to help emphasize intent as wellbut I want to stress that any estimate is just an estimate
The fact that a high-level WotC employee not only recognized these cards, but also happened to have one on an uncut sheet in his possession adds to the preponderance of evidence that the cards are indeed genuine products of WotC
Get your hands on the new Scarlet & Violet Pokmon Surging Sparks SV8 Booster Box (30 packs)