Will Clone Pokémon return to Pokémon Go?

Tons of different costumed Pokémon have appeared in Pokémon Go over the years. Often, they are cycled out again and again. Party Hat Pokémon return for every Anniversary, holiday-themed Pokémon come out Christmas, and so on. But, one type of costume Pokémon has not quite made a comeback yet: Clones.
As an active Go player who often meets up with a group, I always hear about Clone Pokémon and always get asked if they are being released at some point. I think, the want for these specific Pokémon comes from the resurgence in popularity Pokémon Go has enjoyed post-COVID. Now that there is a new wave of players, they want these really cool-looking starters - and who can blame them?

So, when I got the chance to sit down with Michael Steranka, the Senior Product Director at Go Fest, and ask him all about Clone Pokémon in Pokémon Go, Michael explained that as this collaboration was with the anime, it makes it tricky to just put them out on the next Pokémon Day, as they are something of an IP-agreement.
"We are always trying to find opportunities to collaborate like that. We do want to figure out ways to help players fill out their back catalogue of costumes or, you know, things that they have missed. The game has been out for almost nine years, so there is lots that anybody could have missed over the course of the game. But, there are different ways to accomplish that, so we are kicking around some ideas on our side.
We always want to be thoughtful, you know? Anytime we have any costume in the game, it's not just a random thing that we have. Or even, when we bring it back, there should be some type of thematic or relevant tie-in to something happening within the game.
But yes, feedback heard."
A few frequently asked questions about Clone Pokémon:

Clone Pokémon were featured in Go on February 25th, 2020, during the Pokémon Day celebration event, which actually coincided with the release of the movie Pokémon: Mewtwo Strikes Back - Evolution, on Netflix. This gave a fantastic opportunity for a crossover.
What Pokémon can be Clone Pokémon?
Venusaur, Charizard, Blastoise and Pikachu could all be found as Clone Pokémon during the event.
How do you unlock Clone Pokémon in Pokémon Go?Venusaur, Charizard and Blastoise were available in four-star raids around the world. Clone Pikachu was only found in through snapshots, so they were a little more limited.
Can Clone Pokémon be Shiny?No, Shiny versions of Clone Venusaur, Charizard, Blastoise and Pikachu were not released.