As there’s no option to turn off the “news” section in WaveLab, a workaround (use at your own risk, Windows only) is to rename:
%PROGRAMFILES%\Steinberg\WaveLab Pro 12\Components\WebView2Loader.dll
Now the links on the left in the hub open in your choice of preferred browser!
(Credit to @Phillipus from the Cubase forum)