It is normal for standard weights to be based on periodically updated statistics .. eg, the old 170lb per body weight comes from a US study based on the US Army (as I recall) and conducted quite some decades ago ... likewise, subsequent studies have varied the standard weights according to country and typical passenger group. For instance, Australian standard data was updated some years ago following a quite extensive population study done by CASA (John Klingberg's good work) using available medical data in the public domain.
The same consideration applies to baggage weights.
Now, as to whether the tables are applied routinely and appropriately .. that is a matter for others to assess.