I do not think so. It does NOT flag posts it thinks are plagiarized: it merely posts the source and and some automated text.
I made a new post and 
"Hi! I am a content-detection robot. This post is to help manual curators; I have NOT flagged you.
Here is similar content: http://www.theotherpost.biz/Articles/Article-xxxx.html"
What this does in my opinion is that it prompts you to do the needful, (which in this case, when you discover that your post is somewhere else on the Internet, even if you are the original creator) and "add value" to your steemit post, by editing it, that is changing your post to something new, like this observation. Make a new post. You go to edit, change your topic title, change the post to something original, change your tags, and boom you have a new post.
What do you think STEEMERS? Am I right? Do not be afraid to up-vote or down-vote. STEEM CASH is new and we are all learning here. THANKS.