Video thumbnail url without API calls

Oh right. But the only url that can change is the stream url, right? Because both videos and clips uses generated ids that I presume never change (i.e. https://player.twitch.tv/?video=181166032).

What happens if I post a link to a stream on some social platform, for example this one: https://player.twitch.tv/?channel=rains8 and then after some time rains8 decides to change his channel url? The old url stops working, or is it redirecting to the new one?