There's no way to skip the validation and being able to download
updates. Microsoft doesn't allow that, except for non-critical
updates.
Notification part has 2 separate programming. One is you validate
and it turns out to be pirated, it will keep notifying you.
The second one is after you have validated and has been confirmed
to be using a legitimate copy, but MS mistakenly labels it as
pirated products and starts notifying you. This happens all too
frequently, because MS changes the code regularly as hackers
attempts to bypass the WGA.
WGA Notifications is installed immediately you attempt to validate,
and this will happen across all Windows and Office updates sites,
and upgrade sites. To get notification, you have to validate. Never
the other way round. WGA Notifications can be removed, but MS will
still prompt you.
That's why pirated copies of Windows will always be stuck at the
validation stage, because that's what it's supposed to do. WGA
Notifications will just keep alerting you till you get your copy
verified.