As highlighted in T66793#2289607, despite the usefulness of having access to the relevant languages, recommendations always provide a degree of uncertainty (i.e., why am I offered Japanese and not German?).
To provide more clarity, a tooltip is proposed for "more" button of Compact Language links that communicates its functionality as well as some additional context (your choices are captured but the list does not limit to that).
The proposed text is: "All languages (initial selection from common choices by you and others)"
