https://bugs.winehq.org/show_bug.cgi?id=53697
--- Comment #55 from MrNo iddno+winehq@pm.me --- (In reply to nerzhul from comment #52)
retail is now dead until a launcher bugfix. They update and mark retail as incompatible today.
They don't "mark" it. WoW got an update, therfor your client version is incompatible with the server version. That is why it says "incompatible".
As I already said before. Just install a Windows 10 VM and install BN/WoW there and update the game then transfer it over to your Linux system with FTP. Or... if you have a real Windows install somewhere, do it there and copy over the WoW folder after update. Then start the game WITHOUT the BN launcher. It works 100%, I do it every day, I just did it 2 minutes ago with the latest update, too.