I'm aware of it, since someone posted about it on JWFAN a couple of weeks ago. It's a great find, and solves a great many mysteries related to this series.
Many times they can't, because either no link is available online, or the contributor does not submit one.
And even then it doesn't matter. I can't tell you how often I've submitted composer and cast credits with a video link so the submission editor can verify, but they summarily reject it and send me the generic: unable to verify. Kind of tough to verify when you WON'T CLICK TO VERIFY. God, so lazy over there.
Or, on the flip side of the coin, how often I've made submissions (screen accurate ones) that get taken in a minute without verification.