Windows Server 2019 Right click option only offers New Folder in the root drive

Why/When did Microsoft make this change...

probably with windows 8/server 2012 since you can't do it there but could in windows 7

...is there a different fix out there that can be implemented at the domain level?

not broken so wouldn't call it a fix; it is UAC behavior
you can't create items like that (as you could in windows 7) on the root of the drive unless you are elevated and since explorer doesn't work that way, you don't have that option anymore
as far as changing that UAC behavior, you could add a registry item in a GPO for that key

Hello My Proposal into this would be...

If you have enough space on your server just create a new partition.
so
Defragment your C: drive
after it changes the C:\ storage to 150Gb or so and the rest create it in a D: Drive
This will help you to separate the C:\ root from the D: (data) it's a common configuration but of course with a different physical disk but you can make it with a logical disk and you'd skip the dirty of changing things on your brand new server 2019, and get out with whatever you wanna do on the data or sharing side.

The issue is it is Windows 10 and it is not just the root of C: and C:\Windows only it is every folder in the C: drive unless you create it at that time or create a subfolder in it. I can create files if I open the applications as admin in the root and the other folders also i.e. open Notepad as admin and it lets me save the file in the C drive or Windows folder or any other folder. Again I can right-click and create a folder in the Root and then add files to it by right-clicking.

If it was normal behavior it would affect Non-Domain joined Windows PCs this is only affecting Domain joined PCs.

I understand what you are saying. I log in to a non-domain joined PC as administrator and create files fine. I log in to a domain-joined PC as administrator and cannot create a file. I then log in as a local admin to that same domain-joined PC and it still will not allow me to create a file either. This has recently started occurring not 15 years ago on these servers/workstations since I have been working on them for years now and never had this concern until now. I know MS in their infinite wisdom thinks that UAC is protecting us but if you need a file created it should prompt you for credentials not just completely remove the option from the contextual menu.

I understand what you are saying. I log in to a non-domain joined PC as administrator and create files fine. I log in to a domain-joined PC as administrator and cannot create a file. I then log in as a local admin to that same domain-joined PC and it still will not allow me to create a file either. This has recently started occurring not 15 years ago on these servers/workstations since I have been working on them for years now and never had this concern until now. I know MS in their infinite wisdom thinks that UAC is protecting us but if you need a file created it should prompt you for credentials not just completely remove the option from the contextual menu. I understand UAC is the culprit here since I provided the regedit to disable parts of the UAC's validation in my opening statement. I do not want UAC terminated completely I need it operational and I need to be able to operate through it efficiently.