I wonder if this is an example that heavily influenced the Church in the meaning of Satan and not just the well-known meaning of carnal desire, self-indulgence, and freedom.
Very much so. Except that rather than focus on "people", Satanism focuses on the individual
Satan represents people in society who stand up [to] the corrupt powers and in return, get demonized by the authority.
So to rephrase your statement to better reflect Satanism:
Satan represents the individual in society who stands up [to] the corrupt powers and in return, gets demonized by authority.
Except that we do not feel obligated to "stand up" or rebel against anyone or anything unless we choose to. We are not martyrs and are not interested in hopeless battles or pointless wars that do not serve us.
Satanists are selfish that way.
These issues are discussed in some detail in most of the Church literature to include The Satanic Bible
and The Satanic Scriptures
I would urge you to read and study them as you have already gained some insights that are promising.