> It seems more likely to me the manager tried to read it and struggled, then generated something of equivalent size or larger.
Either way, it's poor management to interpose oneself between employees. As a manager you should be connecting groups of people to talk to each other directly, not injecting oneself as a go between. If they have issues understanding the material they're much better off asking the OP directly than asking the manager who doesn't understand it either. And they'll be in a much better place to do that if they have read the material OP actually wrote.
The difference is that mj was trying to give advice to donatj, and donatj can't control what their manager does. So the advice is crafted such that it gives actionable suggestions to donatj.
Yet, that might not be the correct interpretation. I don't know, I'm some third party, like you. Personally I agree that this is poor management but I don't think just blaming the problem on the manager solves anything, it just leaves the problem broken. So the things to do are either fix the problem or figure out how to work with the broken thing.
Well, OP can learn from the experience or turn it into a hill to die on. Learning doesn't imply you were ever wrong, only that something you did produced an unintended result -- people are themselves problems to navigate around, not people whose actions you have to read as judgements.