>an alternative version of windows 10...without "telemetry"...windows 7 will be the last microsoft OS I ever install on bare metal
You know all the telemetry was backported to 7 and 8 right? You can remove it but that would fall under "3rd party add-ons to disable this behavior" and thus would not satisfy your needs.
Yes, updates. If you memorize all the KB123456 numbers associated with telemetry you can block them or uninstall them; however again you can mitigate them in 10 as well.
You know all the telemetry was backported to 7 and 8 right? You can remove it but that would fall under "3rd party add-ons to disable this behavior" and thus would not satisfy your needs.