Here's my question: why did someone delete my post? Whoever did it, just tell me!
The answer you posted just before asking this question was deleted because it gained "rude or abusive" flags. It does appear that you have not been stung with the 100-rep penalty which I would expect for the post being flagged and deleted. However, that sort of post is not tolerated and will be removed.
If this Meta post is actually about the other deleted answer, it gained three downvotes and no upvotes.
I think that each is an adverb. But that's my answer. It depends on how you use it in a sentence. If you use each to describe a verb, adjective, or adverb, it is an adverb. You have to ask yourself these questions: is the word telling how,where,when,what,to what extent, or under what condition? If it tells you one of those things, it is an adverb.
It was deleted by a moderator; not me, but I can explain it. It started out with "I think...", whereas what Stack Exchange seeks and encourages are knowledgeable answers. It continued "I think that each is an adverb. But that's my answer" which is a bit short, so you then attempted to justify it.
Your answer doesn't actually answer the question, which was "It seems that each is an adverb in (1) but a pronoun in (2). Can anyone explain why each is not a pronoun in (1)?" In your answer, you are telling the OP how to judge an adverb, but a good answer would actually explain how each satisfies that test.
In any case, unfortunately, it's actually wrong. This is indicated by the downvotes and the fact that it contradicted the top-voted answer, given by a professor of English at an American university.
So the answer was deleted because it was not authoritative; did not really answer the question asked; and the answer it gives was judged to be wrong by the community. Deleting it saved you from further downvotes and the two-point penalty which accompanies them.
Stack Exchange is not a discussion forum where opinions can be shared. It is a Q&A network, where questions asked can expect authoritative answers. The community, and moderators to a certain extent, curate the content.
You are probably not aware that new users' answers go into a review queue where they can be assessed by more experienced members of the community. There are also flags generated for late answers (which I believe is defined as more than six months after a question is asked) and those also get special attention.
As a general rule, it is not a good idea to answer a question three years old, or which has an accepted answer (unless that accepted answer is demonstrably wrong), or where your answer falls short of a highly-respected answer to the question. When you do answer, the answer must actually answer the question, be authoritative, contain its own justification, and be detailed.