This was really helpful, thanks!
PTCG and PTCG2 had four powerful, legendary cards, all illustrated by Sugimori: Dragonite, Articuno, Moltres, and Zapdos. Each of these arts were originally considered for Fossil, but later changed in favor of Arita’s Articuno, Moltres, and Zapdos, and Himeno’s Dragonite. It makes sense to use this Sugimori Dragonite for the GB promo given its direct relationship to the game.
I wish these early conversations among artists/game developers were documented!