I dunno.
www.tsr.com still works. And it's been 15 years now since that was a thing.
So is myspace.com, but good luck trying to reach anyone you used to know there, let alone one of their dope tracks. IPs change hands, D&D could be sold off, who knows.
My point was that URLs are transient. Domain names less so, but companies, especially RPG companies, do go under, bought out, split up, or dissolve or change focus. I wouldn't even expect the 4th ed character builder to be accessible from their site in a couple years time as it becomes unprofitable for them to do so. And hosting videos on your own server is a good way to have it crash on launch day. Have you ever launched a huge product online? I bet they'll put it on YouTube instead. But then you're back to the old "will youtube be around in ten years?" Fifteen? Twenty?
I'm happy with the Starter Set not having throwaway materials in it, but I consider URLs to be throwaway junk that I don't expect to be valid for long. I'm just too experienced with the internet to assume things will stay put. Quite to the contrary, it's practically a given that they
won't.
The less online tie-ins for D&D 5th the better. Having some tutorial videos online is fine, but the core product shouldn't rely on those to help newbs understand how to play the game. Back in my day, we didn't have no youtubes to learn how to DM, we figured it out. It's kind of silly to think that newcomers can't figure it out either. Most of the time you learn to DM from someone who already knows how. That's kind of the whole point, to interact with human beings face to face and have fun, share knowledge and kick some goblin butt.