The relationship between the Default Mode Network and a rich inner life seems like a reasonable enough connection, as does the relationship between DMN activity and loneliness.
What would be fascinating to me is an exploration of causality.
Can feelings of loneliness be increased by an upregulation (dTCS) of Default Mode Network activity? Can they be reduced by a downregulation? Can either of those be performed without substantially changing the subjects conscious qualia or internal states?
This will be really interesting to watch in a few years.