I'm also a publisher.

I believe that if the video ads cannot be closed, it will worsen the user experience and drive users away from my site. That's why all video ads that you see on sites, are popups that can be dismissed with an X button. Sites don't try to stop you from closing these because they also know that video ads are generally annoying to users.

But for video ads, they had better have a higher CPM than static ads.