It's difficult to get this right, isn't it? On one hand you want to be inclusive and make the songs accessible to all, but there's a risk of it becoming prescriptive and limiting.
At our local singaround, the landlady suggested that each of us learn a chorus song that we could do every week, so that we all got to know a core repertoire. My heart sank at the idea of singing and hearing the same songs every week. Fortunately no one took any notice, and we continue to have a mix of new and better known songs.

Marje