It wouldn't surprise me that what seems like whole things from the outside are split up even further on the inside of Microsoft. There's probably no single person responsible for microsoft.com (nor was there at the time). Instead the front page is one team, Windows Update (at the time) was yet another team, and sales another, and then there are 5 other teams doing other things, and no single individual or group is responsible for the whole thing. They've all got permission to push things to the website and change whatever just from time immemorial, and not through any defined authority, since that authority doesn't actually exist.

You can still see symptoms of this today. MS will (or at least would) spin up new domains rather than just update microsoft.com, or create newthing.microsoft.com, since both of those require talking to whomever is responsible for the main domain. Even if that person exists, knowing who they are in an org like MS is already a big ask when it's organised the way it is. Meanwhile, buying a new domain likely takes less than an hour, even if you include billing and such.