I’ve been using Toad for over 5 years and while I can’t remember that far back, The last half dozen or so upgrades at least have never transitioned my Editor Highlighting Styles. Mostly everything else I can tell migrates fine, but I still have to manually copy the xml file from the old version to the new. Location for those also experiencing this:
%USERPROFILE%\AppData\Roaming\Quest Software\Toad Data Point 4.1\Templates\Languages