It's fine for some decisions to be made by mods only, but keeping it quiet and rolling the changes out all at once when the decision is final seems to cause nothing but problems. It means the mods and admins are caught off guard when the users have strong objections, and have to scramble and backtrack to deal with the backlash. A heads-up about what changes were being discussed would have let the mods be aware of what complaints would be made while they were still in the decision making process. Then when the changes are made, they could already have measures ready to address the concerns, or at least consistent explanations of why the changes where necessary. Instead they had to quickly throw out multiple conflicting justifications, and added to the confusion.

If you're surprised the users saw this as more than a tiny change, an announcement that a discussion was happening could have given a warning of what to expect.