Nope, sometimes it asks for normal videos as well, it really depends on the case since there’s a lot of background stuff happening, making the experience vary between users.

No, not age restricted.

Happens most frequently with using any VPN, which we use all the time at work and I often use at home or while traveling.

But sometimes it just does it without.

I think most people are signed into their gmail account or have been recently so the cookie is set. It's crazy when you don't have one how hard Google pushes you.