There are tons of projects that have been shut down and even sued for doing fan games, just because some didn’t get shut down doesn’t make it safe to do.
A quick google search gives multiple fan made pokemon games that got shut down by Nintendo. Pokémon Prism, Pokémon Uranium and Pokénet were just the first three results I found.
Put your talent towards making an original game inspired by Pokémon instead so you don’t have to worry about suddenly getting shut down and sued for your hard work.