Even if a person hardly is producing any stomach acid
at all, if any of the tiny amount of stomach acid
should go backwards up
into the esophagus, this tiny amount of stomach acid will burn & damage the esophagus.
If a person has no stomach acid at all (due to acid blockers, etc.), any bile in their stomach, could "reflux", and cause esophageal damage!
So, reflux is harmful to the esophagus, whether it is acidic, or alkaline reflux.