My understanding is that the list of related names comes from WeRelate, although in the past it hasn't been updated very frequently - see https://www.wikitree.com/g2g/1122012/something-mechanism-suggests-potential-duplicates-creation?show=1127244#c1127244.
If you want to suggest a name variant to WeRelate, which should eventually make its way through to WikiTree, it looks like the place to start is https://www.werelate.org/wiki/WeRelate:Variant_names_project.