I've been using the term meatspace since at least the 90s, and would be semi-shocked if it didn't exist in either 80s sci-fi or posthumanist manifestos or whatever in some form or another.

Here are some concrete examples courtesy of an etymology site: https://wordspy.com/words/meatspace/

The use of "meat" to characterize the physical, analog, arbitrary, biological (as opposed to the logical, digital, formal) pre-dates the 80s/90s deliberate apposition with "cyberspace" afaik, but I don't have time to fish up concrete examples from my library atm.