Pokémon is the biggest multimedia franchise on the planet, with multiple branches in the video game, animated series, movie, trading card game, and comic book worlds. The video games are what kicked off the Pokémon franchise and they have their own canon that is separate from the animated and printed franchises. The Pokémon video games have bizarre lore that is considered to be canon, which is buried away in brief moments that are easily missed.
The Pokémon series has never been afraid to retcon elements that no longer fit with the game world. The most obvious of these are the instances when new types were introduced to the series, like when Dark-type and Steel-type Pokémon appeared in Pokémon Gold and Silver, and when Fairy-type was introduced in Pokémon X and Y. These were integrated into the world with barely a mention as to why they were never around before, with remakes including the new types, even if they weren't in the original games. The way Pokémon evolution stones are used also falls under this category, as they replaced some of the more annoying evolution methods used in older games.
The Pokémon world might have become more sanitized over time, but there are still weird and dark elements that are part of the series. The Pokémon Company still allows references to humans eating Pokémon, and there are still Pokédex entries that talk about Pokémon eating each other, or killing humans in the wild. There are some pieces of Pokémon lore that are equally as weird, yet they still exist within the games.
The Pokémon World Has Competitive Cheating Scandals
There are plenty of Pokémon trainers who unofficially cheat, thanks to quirks in the programming of the games. The Elite Four in Pokémon are known for cheating, with Lance of the Kanto Elite Four being one of the worst, thanks to his Dragonite that knows Barrier. He would go on to be an even bigger cheater in Pokémon Gold and Silver as the Champion, where three of his Dragonite would be under-leveled, as they were all under level 55 (the level when Dragonair can evolve). Thankfully, this has become less common over time and enemy trainers will abide by the same rules as the player.
It turns out that there are actual cheating scandals in the Pokémon world. In The Isle of Armor expansion for Pokémon Sword and Shield, the player encounters a kindly old man named Mustard, who offers guidance to those who study at his dojo. It turns out that the final boss of The Isle of Armor expansion is Mustard, as he was a former Champion of the Galar region. The details of Mustard's time after being Champion are easy to miss, as they only appear on his Rare League Card. According to the card, Mustard was once asked to take part in a rigged match by the chairman of the era, prompting him to retire from the Pokémon League. This is the only indication of a Pokémon battle being rigged in the series and it's a shame that it's buried in a fleeting reference that's easy to miss.
The Real World Exists In The Pokémon World (But Is Slowly Being Replaced)
The creators of Pokémon Red and Blue had no idea that the games would become as successful as they would. The original intention was for Pokémon Gold and Silver to be the final games in the series and end it all with a bang, but the exploding popularity of the franchise around the world meant that the series would continue to this day. Pokémon Red and Blue are set in Kanto, which is named after a real place in Japan, so it's easy to assume that the Pokémon world was once meant to take place in the real world. This is why some Pokémon have references to real places and animals in their Pokédex entries, such as Raichu's mentioning an Indian elephant in Pokémon FireRed and LeafGreen.
As the Pokémon series progressed, the new regions started to be based on places outside of Japan, with Unova being based on New York, Kalos on France, Alola on Hawaii, and the Galar region on the United Kingdom. This has led to some retroactive changes in the remakes. In the old Pokémon games, Lt. Surge was referred to as the "Lightning American" on the sign outside of his Pokémon Gym. In the Pokémon Let's Go games, Lt. Surge is no longer American, and he's now referred to as the "Lightning Lieutenant". The Silph Co. agent who references Russia in Pokémon Red and Blue and Pokémon FireRed and LeafGreen has also had this reference removed in later games. It seems there is now an effort to slowly phase out the real-world references in the Pokémon games.
Humans Used To Marry Pokémon
The Pokémon video games have never referenced potential romance between humans and Pokémon, at least not in the English language versions. There are romantic human couples seen in the games, with the player even interrupting Misty while she's on a date in Pokémon Gold and Silver. Pokémon can breed with each other, but it never crosses over. Surprisingly, this is something that has come up in the Pokémon movies, albeit in a tame way. In Pokémon Heroes, a Latias kisses Ash on the cheek while taking on the form of a human girl, but this is treated in an innocent way by the story.
The creators of Pokémon Diamond and Pearl had other ideas. If the player visits Canalave Library, they will find books that detail the myths of the Sinnoh region, which discuss the history of different Pokémon. In the English localization, one of the books talks about humans and Pokémon once ate at the same table as equals, but in the Japanese version of the game, the story mentions that humans used to marry Pokémon. This was one instance of the Pokémon franchise being censored and it's probably for the best that it was, even though this was after the time period when the Pokémon franchise's content was being scrutinized.