I'll hedge this by saying I can only speak for the teams I've worked on, plus my somewhat limited understanding of company-wide policies.
The answer to both questions is no. If you opt out, your data is not used for modeling or targeting or anything. Perhaps some internal reporting that isn't used for anything other than like PMs wanting to understand user behavior? Even that I'm not sure about.
If you are identified as being in market for something based on activity and then opt out, you will no longer be classified as being in market. That classification will be deleted- though perhaps not immediately but within some reasonable time frame, say 24 hours or so.
What if someone is identified by a model as being in market for a TV and then opts out? Would they still be classified as in market at that point?
I work in digital media, feel free to get technical with your response.