Still having trouble with this one. Clearly not all of the districts count.
Here is a screenshot with a Cultural District surrounded by six unpillaged districts including a Government Plaza and a Spaceport. The achievement did not pop.
I loaded an earlier save from the game and replaced the Government Plaza and Spaceport districts with an Encampment and a Holy Site. The achievement still did not pop.
Perhaps the Entertainment District is not counting?
At the end of the game I unlocked the Captain of Industry achievement, so the game is unlocking other achievements properly.
Can someone who has finished the Meiji Restoration achievement please share their wisdom on how it can be done?