Mikrotik - redirecting YouTube to a local friendly page

Solution 1:

If you don't have administrative rights on the client, you can't. (because it's considered as an attack)

If you have administrative rights on the clients, you can install there your own certificate authority, and use a certificate signed by that certificate authority to redirect users using https (So you will comply with HSTS, and HPKP/PKP is bypassed for locally imported root).

If it's a hotspot with a welcome page, you can explain on that page why some websites are blocked. (See https://www.chromium.org/chromium-os/chromiumos-design-docs/network-portal-detection )