I think so.
Keep in mind, MS sells $90 billion of product and services a year, so we're talking less than 3% of that. (MS cost of revenue is about a third of revenues!)
1] First imagine LinkedIn used as the primary sales channel for MS products. Head of sales is probably salivating.
2] And then there is advertising. I think part of the reason LinkedIn is valuable is this: apart from LinkedIn there is no simple way (barring credit cards or other documents) to verify if an account who signs up to an online service is a real person, or who they claim to be. For an advertising business, this is gold: Expect the LinkedIn federated sign on to be integrated into many microsoft services (and by more third party services.)
Strategically if you are selling software/anything, you have are better off targeting the top 10% of earners rather than a gazillion broke teenagers.
Of course there are fake profiles on LinkedIn, but they are minor, and weeding them out is probably easier than on other platforms.