The Pokemon Company banned Porygon's debut episode," Computer Warrior Porygon," nearly 25 years ago, as it contained explosions that appeared in the form of quickly flashing lights, which inadvertently triggered seizures in children across Japan. Since Porygon headlined the episode, it, unfortunately, ended up in the crossfire of The Pokemon Company's decision, and thus the Pokemon anime hasn't featured it since. But if certain predictions about Pokemon Journeys turn out to be true, then Porygon's fate may change soon.
The Pokemon fan community "Anipoke" posted translated synopsis' for Pokemon Journeys' upcoming episodes 78 and 79 on Twitter, and the episode 78 synopsis describes an episode that seems perfect for Porygon's return. It states that Ash and Goh will investigate an issue involving the Pokemon research data they've collected for Professor Cerise. The duo, namely Goh, suspect foul play when evidence suggests someone logged into the Professor's main computer just before all of the data went missing.
There's a good chance for Porygon to be the culprit behind this "heist" because it and its evolutions are entirely made up of code, and as such, it can freely travel through cyberspace. It did this in its debut episode, which accidentally caused a Pokeball transfer machine in a Pokemon Center to malfunction. If Porygon transferred into Professor Cerise's computer in this upcoming episode, that could explain why the Pokemon research data Ash and Goh collected disappeared.
Of course, the synopsis for Pokemon Journeys episode 78 doesn't specifically state that Porygon is returning. It's possible that some random electric-type Pokemon caused the problem, or maybe even Team Rocket built a machine to steal the data in another one of their elaborate schemes to please Giovanni. They're several different routes the episode could take, and since it doesn't premiere until August 27, fans have at least two weeks to wait before seeing any promotions or evidence suggesting that Porygon will be one of those routes.
That said, now would be the perfect time for the Pokemon anime to reintroduce Porygon. "Computer Warrior Porygon" aired so long ago that everyone affected by it is well into adulthood by this point and probably don't care about the Pokemon one way or the other, and since Porygon itself had nothing to do with what happened, there's no real reason to keep it banned. As Pokemon Journeys has been all about surprise appearances, this episode, thanks to its content, would be the perfect opportunity for Porygon to make a comeback.
Pokemon Journeys is airing now.