They should be the same. I guess that "Monopoly The Classic Edition" has been renamed to "The 1980's Edition" in order to avoid confusion with standard (non-retro) Monopoly that's also sometimes called "Monopoly Classic Game" to differentiate it with themed variations, as you can see here https://www.amazon.com/Hasbro-Gaming-C1009-Monopoly-Classic/dp/B01MU9K3XU
I believe the retro edition is not produced under name "Monopoly The Classic Edition" anymore, and all places that still sell it just have old stock lying around. The producer Winning Moves Games also only lists "The 1980's Edition" on their homepage https://winning-moves.com/product/monopoly1980sedition.asp