Don't underestimate the disruption that can be caused by several thousand PCs trying to download the same windows update at the same time over the same internet connection. Patch management is a bit of a tricky thing to get right, apart from the issues you mention.
They don't though do they? If they're on a domain, they use a locally cached version of the update(s). Win SCCM or whatever it is manages shit like that, right?
Don't underestimate the disruption that can be caused by several thousand PCs trying to download the same windows update at the same time over the same internet connection. Patch management is a bit of a tricky thing to get right, apart from the issues you mention.