The forums are designed to generate player to player discussion - preferably constructive. Posts that intentionally cause arguments, fights, harass/insult others, etc are trolling. Same with posting an “unpopular opinion” just to stir up trouble.
If your post was actually deleted by a moderator then it means it broke the rules. If it was just greyed out and you got an automated forum system message then it means people reported it (possibly falsely) and a Mod will review it.
If your post was just greyed out (people have to click to see it but it is not deleted) then it means players reported it - but that a mod did not remove it or penalize you. Often if it was players abusing the flagging system the mod will un-grey the post and possibly punish the false flaggers.
Players have no power - other than to flag. Mods are held to Blizzard policy.
If you feel a forum punishment (actual suspension), was in error you can appeal that via the link in the email you would have received.