Modern macOS versions (Catalina and later) do not support 32-bit apps. Since the 1.12.1 client is 32-bit, it will not launch natively on recent macOS versions.
If an end-user attempts to run the "WOW 1121 client mac" today, they face significant hurdles: wow 1121 client mac
For versions of macOS like Mojave or earlier that still support 32-bit apps, or for users who prefer the stability of the Windows client, Wineskin is a popular choice. Modern macOS versions (Catalina and later) do not