Pokemon.com published an article about Tag Team GX cards from SM11 Unified Minds interviewing Atsushi Nagashima, the Pokémon TCG game director at Creatures Inc.
The director basically confirmed the existence of a Special Art version of both Espeon & Deoxys-GX and Umbreon & Darkrai-GX at some point in the future. While he did not mention Espeon & Deoxys-GX specifically, he did mention Umbreon & Darkrai-GX. Which are both a set (Released in Tag Team GX Starter Decks) and counterparts of each other.
Quote from Atsushi Nagashima;
"When we imagined Umbreon and Darkrai, we envisioned them standing side by side on the streets at night, and we were convinced they'd make a great TAG TEAM. For the special art, we're planning to make an illustration that showcases that kind of image."
Time will tell how these cards will be released, probably in a product like a Premium collection or a tin. Or maybe in the main set of SM11 Unified Minds? What do you think of a Special Art version coming for these Tag Team GX cards? Let me know!