The NY Times Hua Hsu gives an overview of "rediscovered" old school classic material with a focus on Top Shelf 8/8/88:
An album called “Top Shelf 8/8/88” was issued in Japan. Supposedly a collection of never-before-released recordings from 1988…

The album’s liner notes told this story: An unidentified New York hip-hop aficionado scavenging through a storage locker near Hoboken, N.J., discovered a box of studio reels. The only clue to their contents was a name scribbled on a label: “Fab Five Freddy,” the hip-hop impresario who was host of “Yo! MTV Raps” in the 1980s.

According to the story, the reels turned out to be recordings from hip-hop’s fabled golden era, taped at a studio called Top Shelf in a basement in the East Village of Manhattan. The reels were supposedly lost during the Tompkins Square Park riots of 1988, and the studio later shut down.

I love the Tompkins Square riot reference, boy does that take me back!  And both the Japanese release and the storage locker in Jersey angles are priceless.

Fab Five Freddy seems to be involved or, at least, going along but Dres of Black Sheep says it was a hoax that he’s enjoyed being a part of while Afrika Baby Bam of the Jungle Brothers says:
"We still remember the culture and tradition," he said. "How much more do you need, outside of the actual date, to make a record as authentic as you would have made on Aug. 8, 1988?"

I guess I could go on a sarcastic rant about authenticity but mostly I think this is another sign of Old School/Golden Years resurgence as a marketable commodity.  And a fun hoax.