There must be something more to the "western Azerbaijan" remark,
because the phrase is too heavily laden with baggage to have been
an unintentional use.
First off, Azerbaijan is split into two parts, with a western province
separated from the rest of the country by Armenia.
Map of Azerbaijan
Map of Armenia
Azerbaijan claims that all of Armenia should really be part of
Azerbaijan. The phrase "western Azerbaijan" could refer to Armenia
itself.
Nikol Pashinyan's campaign claim that Serzh Sargsyan is trying to
transform Armenia into western Azerbaijan strikes me as an extremely
bitter accusation, evoking the horrors of the 1989-94 crisis war
between the two countries.
So I feel pretty certain that Nikol Pashinyan's saying "western
Azerbaijan" refers to a lot more than just corruption.
Then there's one more complication:
Map of Iran
The northwest province of Iran is named "West Azerbaijan."
This is similar to America's state "New Mexico."