Sorry for the delayed response. I've also found that the results don't match what was on my profile page and have been trying to a construct a query that matches those results. Unfortunately, I don't have anything that resembles the actual profile updates. However I did notice that the profile page is not pulling some of its information through an API.
For example, comments are being pulled through:
http://profile.yahoo.com/{guid}/comments/
And reading activity:
http://profile.yahoo.com/{guid}/reading_activity/
It's possible these are exposed through the social.updates table. I'll see if I can reach out to the Social team for some additional insight. In the meantime, you might be able to scrape the data you want from those respective URLS using the data.html.cssselect table or with some other solution.
Best,
Daniel