This is actually a feature of the .inf by design, an AddSoftware directive. It can even link to apps from the store instead of bundling them with the driver. This is designed to install settings panels like the ones for GPUs.

https://learn.microsoft.com/en-us/windows-hardware/drivers/i...

I guess that from Microsoft's perspective, the driver itself wasn't suspicious, but it installs a questionable sidecar app they would have never vetted anyway.