Despite the undead being commonplace and known in this world (as described by the narrator), the two ghosts here are extremely effective as vehicles for discussing societal issues as seen by Mr. Rodriguez.
I found the idea of a "professional ghost" just as humorous and strange as Mr. Rodriguez did at first blush, but it's quickly belied by Stephan's disruptive and destructive nature. The landlord's decision to change their living space into a vacation rental is a double whammy of upturning in the friends' lives (or, uh, unlife for Gregorio).
Gregorio was a victim of political violence in decades prior, Mr. Rodriguez has to deal with sprawl and pollution, and the pair are both upended by gentrification. Same shit, different day.
I'm just glad that Mr. Rodriguez did some quick thinking to prevent his friend from turning into a mindless husk (or worse, a ruthlessly exploited person). Also, I learned new Mexican slang!
+1