It appears another "gigaleak" has gone down, involving Nintendo. According to sources online, it appears that Game Freak has been hacked, resulting in internal data from the company being leaked to the public. Those involved in the hacking community or those within general Pokemon related groups...
It’s beta builds of old games. It’s only valuable to super fans who wanted to see what could have been.
There are leaks of 3 future games also. Gen 10, 11 and a MMO
I thought the leaker saw those and decided to not reveal too many details other than they exist? There’s a sentence about it in the article.