Quantcast has more accurate metrics for Vox sites (comscore is just guessing, but Quantcast actually gets data from the sites directly).

It reports 81M US visitors/month for the entire Vox network (https://www.quantcast.com/p-d9vfr8QTWnv1E) and 13M for The Verge (https://www.quantcast.com/theverge.com).

That actually lines up pretty closely, so it's likely they were talking about US visitors rather than global (which is ~2x for The Verge).

(Disclaimer: I used to work on Quantcast's measurement product).