Could it be...

...that the term "classic" gets thrown around to describe every hip-hop album that contains more than 4 memorable/replayable tracks?
Absolutely. Sometimes it doesn't even have to have 4.
3 hot records can do it. Like Flockaveli: "Hard In the Paint", "No Hands" and "O Lets Do It" (and I can honestly say I only ever gave a fukk about Hard in the Paint). Have you tried to listen to that album in full? It's unplayable trash.
The word 'classic' doesn't mean anything anymore. and frankly, it's a "Source" term. Our generation is gone.
Frankly, I think the new gen should use their own terminology to describe what albums mean to them. That's what so weird about modern rap. The new kids want the props of the old folk, but don't want to learn the nuances of great old folk stuff. Hence this rap fusion weird middle ground we're at.