Completely disappeared Adobe Photoshop Classic from the computer, and from the Creative Cloud :(

Due to a policy change in May of this year, Adobe removed legacy versions from the Creative Cloud Desktop App. Going forward, we have access to the current and one previous version -- 2020 and 2019.  CS6 is not receiving updates anymore and was removed from the Creative Cloud. 

There is no such thing as Photoshop Classic... do you mean Photoshop CS6?

Supported https://helpx.adobe.com/support/programs/adobe-support-policies-supported-product-versions.html
https://community.adobe.com/t5/Premiere-Pro/FAQ-Prior-major-releases-of-Premiere-Audition-Prelude-and-AME/td-p/9479508

If you have a serial number for CS6 (or an earlier program) try the link below

https://community.adobe.com/t5/Get-Started/Can-I-download-my-older-apps/td-p/10689585