These are cool ideas, Paul, and I hope MS picks one and brilliantly executes it.
I also bet LI will see a huge amount of activity as people scramble to update their profiles to get rid of the lies and BS and title/role inflation and dodgy skills, certifications and recommendations. Most of my “corporate friends” use LI in place of an online CV (and hope HR never looks) and many companies allow for job applications via LI. We used to joke that it was obvious that someone wanted to leave the company when they started updating their LI profile (LI of course emails those updates to everyone in their network).
As a corporate user I would be very worried that MS knows which job offers on LI I am looking at. The data in LI is only as good as its recency. If people stop trusting LI, stop keeping it updated and revert to private email, this deal will backfire.