As the article discusses, the major characteristics of human populations in the recent past centre around demographic changes i.e. small populations where drift dominates, giving way to massive population expansion, where mutation and drift likely play a much more powerful role than selection does (for nearly neutral variation, which is the vast majority of variation).
This could potentially change if the human population ceases its expansion, stabilizing at a greatly increased level for a long period and with high levels of gene flow. In this case, selection could have more of an impact on nearly neutral variation than it previously has.