Is it possible for you to test those URLs again? This is what I’m currently seeing from a server in Frankfurt (wget output edited to just show the redirects):
wget 'https://youtu.be/KCyIfcevExE'
--2021-04-06 19:03:39-- https://youtu.be/KCyIfcevExE
Location: https://www.youtube.com/watch?v=KCyIfcevExE&feature=youtu.be [following]
--2021-04-06 19:03:39-- https://www.youtube.com/watch?v=KCyIfcevExE&feature=youtu.be
Location: https://consent.youtube.com/m?continue=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DKCyIfcevExE%26feature%3Dyoutu.be&gl=DE&m=0&pc=yt&uxe=23983172&hl=de&src=1 [following]
or
wget 'https://youtube.com/watch?v=KCyIfcevExE'
--2021-04-06 19:05:45-- https://youtube.com/watch?v=KCyIfcevExE
Location: https://consent.youtube.com/m?continue=https%3A%2F%2Fyoutube.com%2Fwatch%3Fv%3DKCyIfcevExE&gl=DE&m=0&pc=yt&uxe=23983172&hl=de&src=1 [following]
--2021-04-06 19:05:45-- https://consent.youtube.com/m?continue=https%3A%2F%2Fyoutube.com%2Fwatch%3Fv%3DKCyIfcevExE&gl=DE&m=0&pc=yt&uxe=23983172&hl=de&src=1
Location: https://consent.youtube.com/ml?continue=https://youtube.com/watch?v%3DKCyIfcevExE&gl=DE&hl=de&pc=yt&uxe=23983172&src=1 [following]
(i.e., those two URL formats are now also redirecting to the consent page)