They may include Maoists as well.
It's more of an "era" in leftism than an actual coherent movement.
But they tend to be anti-Soviet and influence our opinions about the Soviet Union nowadays as well.
For example:
You never hear about how the Soviet Union really helped African liberation during the 50s, 60s, 70s, and 80s.
Or how they really excelled in the physical and social sciences.
You only hear about the bad, like Gorbachev and some of the revisionist factions in power at the time.