Yes but no. The head of the Jemad (Joint Services) was straight onto the press to say in effect just that.Was this not refuted by senior serving officers who alleged the original authors were well past their sell by date and it was all a storm in a tea cup. Item in The Times this week I believe (behind paywall)
However the point isn't that it was a few retired crusties, especially when a follow up letter from 217 other officers expressed sentiments of the unity of Spain being in danger. In reality it's just a budget vote in Parliament in a special situation not secession.
It does show that there is an underlying sense of intolerance to those who don't subscribe to a certain mindset and demanding conformity.
An American lady I know who has spent a long time in various countries told me that she was horrified by the underlying current of fascism in Spain.
Look at the reaction to the Catalan referendum. I've speculated more than once if the police had been given the order to use firearms if they would have.
Spain does have an intolerant streak, I'm interested in where else it can be found.