Funnily enough, this is almost exactly how ads are served to you. Advertisers get your profile, try and figure out how valuable an impression will be, bid against other advertisers, and the winning bid gets to show you the ad. All within the fraction of a second of a page loading.
You may have seen in the last few weeks that Internet Archive is trying to raise public support and funds for a legal fight. The thing they are being sued over? Exactly that: https://en.wikipedia.org/wiki/Hachette_v._Internet_Archive
To save your time for anyone who had the same brainwave I had: Multiplying the length of the Blank Space video by 95,081 gives you 300 days, 10 hrs, 18 minutes and 33 seconds. So the wait time is close. Maybe they're counting on 1% of people dying during the wait.
Maximum concurrent viewers for a given video could be a way to lower stress on YT servers, requiring less servers thus costing less to maintain, thus less ads/more money for creators, at least in a more rational and less greedy world.
If scheduled programming vs on demand was something that channel owners or users could pick for themselves it would be an apocalypse or a new golden age for YouTube.
How about you gotta upload one video to watch one video. If you want to watch a video that has been watched two times you need a video that has been watched two times or a longer by two video that has been watched once, or two equivalent videos watched once time each.