What exactly has been fixed? And in what program? What exactly «It still does not work on anything older»?
Are you talking about the program Microsoft Remote Desktop? If so, it has been fixed so that the latest version does not work correctly.
I have on my server installed OS Windows Server 2012 R2, and on my client mac installed OS Sonoma v. 14.4.1.
If you use modern versions of the program Microsoft Remote Desktop (v. 10.9.6 or v. 10.9.7), the printers are not visible in the print dialog in the user program.
And if you use an outdated version of the program Microsoft Remote Desktop (v. 10.2.7), the printers are visible in the print dialog in the user program.
I demonstrated all this in the screenshots above.
Therefore, the program Microsoft Remote Desktop in terms of redirecting printers needs to be fixed as it was in the version 10.2.7.