Administrator Interpretation

The U.S. Department of Labor issued today an Administrator’s Interpretation of the FMLA Regulation defining "in loco parentis" relationships as part of the FMLA’s definition of "son" or "daughter".  Is this "big news" and, if so, why?  

One could always argue that individuals standing ‘in loco parentis" to a child covered under the FMLA could take FMLA leave for the birth or