I don’t “think” I saw it, thanks. There is no script for a wall history module (please don’t suggest my memory is faulty if you can’t provide the misleading script in question). There are, however, other acknowledgements that this module was present, one such being here. I had used similar code (i.e. .names, .realname, .actionlinks as children of .WallHistoryRail) since November 2014, long before the concept of ‘Fandomising’ anything existed.
Until seemingly recently, the module has been present on all wikis in wall history sections as described. It appears that .WikiaRail has since been removed from these locations so whether that was intentional or a bug is essentially the matter here.