The reaction you are getting is because you appeared to be making a trivial grammar correction in a heavy-handed way. Others presumed that the word was definitely intended as 'it' and that the correction did not merit mention.
Supposing I was making a grammatical comment, what would be a less heavy-handed way of phrasing it?
I italicized the word "it" for the purpose of identifying that word as the part that changed. Is the italicization being interpreted as derogatory vocal stress?
I thought about it before my first response, and I'm not sure there is a good way. Anything that comes off as correcting grammar is difficult to do politely, especially in a mixed group of native and non-native speakers.
I think most people (including me) didn't consider the 'I was declassified' interpretation because there was little else in the parent to suggest it, and because the phrasing was odd. Usually it is information that is declassified rather than individuals.
But if one was to ask for clarification, I think your second comment would be a good pattern: "I'm genuinely confused: did you mean X or Y?" Putting the burden on yourself as reader often comes off better than implying that the writer made a mistake, even if the real problem is that writer made a mistake.
(This isn't to mean that you shouldn't ever bluntly correct writers when they are wrong, just that in the absence of a pre-existing relationship it often doesn't go over well with the writer)
I think I've heard people refer to themselves as being declassified as a shorthand for their career and projects being declassified, thus I wasn't sure how to interpret the original statement.
