What exactly does KB2952664 do?

As long as they stay in the Optional section I'm not worried at all :)

kb3112343 though was a win-10 toe in the door.

JustAnotherComputerGeek,

I totally agree with you.

Many many customers have valid reasons why they do not want/need Windows 10 installed on their computers.

However, Microsoft does not seem to care about their customer's wants and needs.

Microsoft's long term strategy seems to revolve around increasing their revenue via implementing "software a service" (such as selling subscriptions to various, yet undefined, "services"). Windows 10 is the key to that strategy ... and thus Microsoft needs to have Windows 10 installed on a billion computers in order to make their strategy happen ... regardless of whether their customers want/need Windows 10, Microsoft will continue their coercive tactics in order to get Windows 10 installed.

I have my Windows Update setting set to "Never check for updates". Once a month, I manually check for updates ... I review each update in the list, hide those updates that are known (or suspected) to coerce a Windows 10 installation (or attempt to collect telemetry or attempt to update Windows Update), and only install security updates that are known to be safe (in general, any update that is not labeled as a Security update gets hidden). I also run GWX Control Panel in case Microsoft manages to slip something past me.

It's baaaack! And it's time to hide it again. As of February 9, 2019 KB2952664 has been re-released ... again.

I don't want nag-ware ( which = mal-ware ) to be installed on my system. I don't want Windows 10 on my Windows 7 system - ever. I have seen too many systems that have been irreparably broken by the Windows 10 "upgrade". My regular customers are not upgrading, but I'm getting phone calls from new customers whose systems have been broken by the Win10 upgrade. As a result, I need to be able to support many users who for many different reasons, cannot and should not "upgrade" to Windows 10.

While Microsoft says that a system will run Windows 10, the truth is that many manufacturers are not providing drivers for all of the devices in all models of their "old" (like 1 year old and more). And believe it or not, the Microsoft drivers don't work either. What a shock! And so, too many systems are being bricked by the Windows 10 upgrade. Microsoft is telling people that the upgrade will work. People believe Microsoft. They let the upgrade proceed because Microsoft said it would work. The upgrade fails. The rollback process fails. And people have brought me a system to repair for which the only repair is a complete reload. And by then, people don't want anything to do with Windows 10 - ever.

As a result, I need to be able to support Windows 7 until 2020. Not that I'm complaining. I'm just stating fact.

Furthermore, there are some line-of-business applications that are not supporting Windows 10 (or IE 11), yet. Those system should not be upgraded yet.

So Microsoft can't tell me that all systems need to be upgraded to Windows 10, and that I need to allow their nag-ware updates to install. I, for one, am not allowing it.

No, it will be installed from the cloud, and ALL the changes will be incorporated.  NO update needed.

Microsoft could come out with a Windows 10.1 that contains all of the cumulative updates since Win 10.0 was released. That might make reinstalling Windows 10 easier.

But ... version 10.1 might be one of the "services" that Microsoft's  customers have to pay for.

Similarly, when Windows 10.0 reaches end of life, customers might have to pay for a subscription to use Windows 10.1 .... the possibilities for Microsoft to monitize Windows 10 "services" are endless.

Like third-party anti-virus software, Microsoft's customers might have to pay an annual subscription fee to continue receiving Windows 10 support/updates.

What of quality and customer satisfaction?  These may become extinct.