Trying to create a desktop shortcut for the World of Warcraft: Forever beta results in an error message. Trying to fiddle with the WoW Launcher also seems to result in issues.
Thankfully, the old launch command via Battle.net.exe works fine:
Battle.net.exe --exec="launch WoWF"
With this command you can easily create a desktop shortcut or add the game to Steam.
However, there is a catch: If you want to use the Steam overlay or track your time, this approach does not work due to the way Battle.net launches processes.
You will need a tool like bnetlauncher to work around this. Except that bnetlauncher also does not work, so I have fixed up a branch with the required changes.
To start World of Warcraft: Forever, you can add bnetlauncher.exe to Steam as a non-Steam game with the following parameters:
bnetlauncher.exe wowclassicbeta -t 15
This should bring up the Battle.net client, switch to the World of Warcraft: Forever page and automatically “click” the “Play” button to launch the game. The Steam overlay should work and you should be displayed as playing a non-Steam game for the entire duration of your session.