The 1st generation games are well over a decade old. They have long, long, long since been dissected down to the last bit of data and in fact if you are curious as to what was programmed in but never saw the light of day, there are all manner of resources willing to give you all the "juicy" details on such. "Juicy" is in quotes indicating sarcasm because there's nothing particularly juicy about any of it.
Yes, beta material sits frequently unused in the deepest recesses of video games. However, these games are not new. They are not mysterious. They are old enough to be in high school. Any mysteries they did hold were uncovered and detailed if not solved outright years ago. There are no sprites for "White Hand", "Buried Alive Man", the Boogeyman, Jack the Ripper, the Yeti, Bigfoot, the Loch Ness Monster (Lapras notwithstanding) or any other fictional creatures.
Not to single you out or anything, but this entire story is 100% malarkey with only the barest minimum of basis in fact and if anyone reads through it and somehow decides "wow, any/all of this sounds really feasible!" - with a full admission that it's all fiction staring you right in the face, no less - then I really don't know what to tell you.