I read this as:
Looking for a Half-Life Linux distro

Sure, that works too.

But based on OP it seemed to me that the larger intent is to get a Linux workstation set up in an AD environment. He wants to show to his boss it can be done, and this is the most integrated way.

Yes.

First you will need to get the VPN up (or be in the office, in the same network to be able to join the AD domain.

Then you need to join the AD domain using realmd. This will join the computer to the AD domain like any regular windows PC. It will set up the Kerberos client, DNS and everything for you (this part is done in sssd).

Once joined you should be able to access the network shares with SMB.

RedHat and deriviates have good support for this. So I would recommend Fedora Workstation, CentOS Stream or RHEL Desktop to set this up in.

docs: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/windows_integration_guide/ch-configuring_authentication

I just moved to Ubuntu from Fedora Silverblue, for some $reasons. I regret it already.

It is not a lie, it is how copyright works.
If you are against it, then be against it. But do not claim they are lying.

This is why things like CC-BY-SA, copyleft and other licenses exist.

No issues running it in Flatpak so far for light gaming.