Are you talking about the Gold and Silver Beta ROMs? That was months ago, not exactly recent.
You can read a bunch of stuff about it here: https://tcrf.net/Proto:Pok%C3%A9mon_Gold_and_Silver
From what I read back when it came out, it was leaked by some guy either on some Discord server or on 4chan, can't remember which, and then they (the uploader) either quickly removed it or it was limited to a certain number of downloads. Either way, the person who uploaded it was anonymous.
Outside of that, you're going to have to become un-busy and read the Cutting Room Floor page yourself, because I'm not summarizing it. If you just want to see the beta Pokemon, you only need to look through this page: https://tcrf.net/Proto:Pok%C3%A9mon_Gold_and_Silver/Pok%C3%A9mon