There is no function in Launch that provides the same functionality. There is no extension (yet) that provides an outbound link condition either. At this point, the best that can be done is to create a Core > Custom Code Data Element which will return an array of Domains that are considered "Internal" (i.e. not outbound). Then create another Core > Custom Code Data Element (call it 'isOutBoundLink') which will evaluate event.detail.href and return true if its domain is not within the list of internal domains.