Probably. And they even previewed a new song. What you might not know, but what is actually true, is, that this one beat didn't get interrupted by the video ending, but was actually everything they've worked on for LP7 so far. Filip is right about that Dubstep thing, btw. Prepare your... ears.
He probably just went onto spotify, clicked on their most recent album, flicked through the songs and thought "yep, still making heavy music".
Although many people would disagree with this (myself included), it does have far more album sales than any of their other albums, so he could assume that means it is considered their best.
I think it's safe enough to say that the main reason for HT's extraordinary success was the timing of its release. If HT were released today, just how well would it do in the popular music scene? Based on what I've observed up to this point, I would say that it would not stand out and be considered "classic" since its sound would not be consistent with the times. While Nu Metal may have already declined greatly by the early 2000s, it clearly still had some traction in the music scene. Otherwise, HT would not have done nearly as well. All of this said, Hybrid Theory is still a damn good CD with several quality songs, no matter how dated they may be IMO.
I think Hybrid Theory would be very successful right now as well. Something about its sound causes it to stand out from a vast majority of other nu metal/rock albums.
I don't if it would have died, but the bands that openly take after LP's sensibilities would have either never come into existence or gotten little-to-not visibility outside of a tiny niche market.