You cannot use the monetization system for YouTube or other services. In order words, you cannot make money from our products.
YouTube will often note that someone has monetized copyright content, and they will summarily (and properly) close the videos or close the accounts of those involved. You don’t mention if you were using the monetization system, but if you were, you should close the video and re-upload without monetization, or you should disable monetization through the YouTube interface.
Now, I should say that this policy may be adjusted in some ways, in the future. We will be sure to let people know if the policies change. But at the current time, that is what is stated in the Guild Wars 2 Content Terms of Use and that is what should be observed.
We’re not out to “punish” people for posting their videos, but like any company involved with copyright material — from this movie company to that fast-food restaurant to the other book publisher — we take reasonable efforts to protect our IP (intellectual property). Things are likely to change and more latitude is very likely to be given, but not just yet.