What is the Security Update Validation Program?

Not exactly. You get the security updates (second Tuesday patches) a week or two ahead of time and you test it on sample machines.  Especially if you have funky LOB software that gets broken with updating this can help you - and Microsoft - identify issues ahead of time.  You don't push these updates out to all of your workstations, it's a test bed ahead of the normal second Tuesday.   You aren't testing new features, merely ensuring that we all get quality updates on patch (security) Tuesday.