I'd have thought that either: A. They aren't implemented B. They are implemented and can be found at an extremely rare rate (In pixelmon, they were a 1/150 chance, so maybe it is a similar case here) C. This pokedex is lying and talking nonsense https://pokefind.co/wiki/index.php It'd be great if someone can confirm this. I don't wanna be searching for hidden ability poliwag to find out that he isn't even in the game yet.
Hi there, Hidden abilities have currently not been implemented and with that, abilities do not currently work. We are working on improving this but we have a lot to develop, so please be patient while we do so!