Although Galarian/Paldean is the language that fans seem to be the most curious about, different “Pokémon” languages have been around for ages. And I’m not talking about how various Japanese and English words have popped up here-and-there in the anime or manga (nor the language that Pokémon speak between themselves), but bespoke and unique languages that is intended to be seen as human speech.
After all, we wouldn’t want kids to ask their parents “what does ‘PMS’ stand for?” after watching an episode, do we? (For the record, it means “Poke-Mon Ssssss….. senter”.)
As you can see in just the anime alone, the different regions in Pokémon use their own languages, likely to underline in other ways that they’re somewhere different.
So this page aims to collect information about all the different unique languages seen in the various Pokémon franchise media, wherether in the video games, animated series, TCG, etc. Languages which are used a lot will get their own page, such as the aforementioned Galarian/Paldean, but also Lentalian, and (eventually) Hissuian and Pasioan (the region where the Pokémon Masters EX mobile game takes place in).
That said, until I can get a specific page or section built for these languages, PA! Discord’er and Language Research Extraordinare, ElementsnStuff, put together this handy guide of all the different languages, scripts, etc, used in the Pokémon franchise.
Holy crackers, that’s a lot of languages! But as you can see, most of them tend to be cyphers of the Latin Alphabet (A through Z), as it’s also what Japanese romaji uses. However, other Pokémon languages are more than just that, and I hope to explore and expand upon later. At the very least, keep an eye out for various fonts of these languages made by myself and/or ElementsnStuff. That said, sheesh, I wonder what Unovan Unown would look like? Galarian Unown are a lot easier on the eyes, at least! 
If you want to talk more about various Pokémon languages, or if you see something you want to add, feel free to swing on over to The Language Institute over on the PA! Discord! We’d love to hear your ideas and thoughts.