Perhaps it was the hype behind the black-green color combination paired with being not only the last deck revealed during the week but also being revealed quite late in the day by LoadingReadyRun's Magic -specific channel on YouTube
The minimum is almost always where it's at
The Heartbeat of Legend, Mugen Xorn, Bomb Fire Walker, MutinyCrash, Sword & Shield, Sun & Moon, Enhanced Expansion Pack, C, U, R, RR, RRR, TR, SR, UR, HR, PR, AR, Pokka PSA10 classic classic mimosa Pikachu, Tapu Koko, Dedennegx , Zacianv, Arceus & Dialga & PalkiaGX, CharizardGX, Reshiram & CharizardGX Pikachu in a Poncho Mario Celebi, Jirachi, Zamazenta, Zacian, Rayquaza, Raikou, Oranguru Professor's Research (Professor Magnolia), Marnie, Boss's Orders (Giovanni), Lillie, Acerola, Guzma, Boss's Orders, Onion, Poplar, Adult Woman, Rose, Nez, Saito, Dande
This ban by the TCG was likely future-proofing
While most players understandably prefer their creatures to simply have it as a static ability and generally shy away from using temporary invulnerability due to expensive activation costs, this creatures means of self-preservation is much more palatable
Sparky#12345)