Once an update has been removed, Windows 10 will prevent it from installing automatically for the next 30 days, giving Microsoft and its partners time to investigate and hopefully fix any issues. The connection between the PC and phone is over Bluetooth with Low Energy Peripheral mode, which is now a requirement. They'll also need to be running Windows 10 build 1803 or later. It will still be a while before everyone will have access to Windows 10 Android screen mirroring.
With NetMarketshare reporting that 38% (Statcounter reports 33%) of the Windows OS market is still running Windows 7 for the month of February, it's not hard to see why Microsoft is starting to deploy this tactic.
This update will be downloaded and installed automatically from Windows Update. Either way, this does mean that phone screen mirroring for Your Phone and Android is just around the corner, and we'll have a hands-on video showcasing the feature in action as soon as possible. However, if security is a high concern to you, the pop ups will also recommend newer PCs for users to buy which come with the latest Windows 10 upgrade. But so far, the company has only made avaliable a Continue on PC app for iOS, which can let you share webpages on a iPhone to a Windows PC.