Are Reshiram and Zekrom shiny in Pokemon Go?

As part of the Season of Heritage, Reshiram, Zekrom and Kyrurem return as Tier 5 Raid Bosses in Pokémon Go. Now that the Season of Mischief is over, we
Are the current Raid Bosses shiny in Pokemon Go? The Tao Trio are back, starting with Reshiram and Zekrom, but can you catch their shiny form?

Can Zekrom Be Shiny in 'Pokémon GO'?

Reshiram (Pokémon GO): Stats, Moves, Counters, Evolution

Are Reshiram and Zekrom shiny in Pokemon Go?

SHINY RESHIRAM & ZEKROM CAUGHT! SEASON OF HERITAGE DETAILS

Reshiram Pokédex: stats, moves, evolution & locations

Cobalion or Terrakion or Virizion or Reshiram or Zekrom or

Pokemon GO: The Legendary Shiny Reshiram & Zekrom Have Arrived

Shiny Reshiram, Zekrom, Kyurem Come to Pokémon GO in Huge Update

ART] Shiny Reshiram and Zekrom redesigned (read comments for

Reshiram, Zekrom, Kyurem, Yveltal, Regigigas - Pokemon Go