Following cataloging practice, BIBFRAME 1.0 had the usual “in part” sequential relationships used for serials:  absorbedInPart, absorbedInPartBy, continuesInPart, continuedInPartBy, replacedInPartBy, replacementInPartOf.

 

BIBFRAME 2.0 retained continuesInPart and continuedInPartBy but dropped the others.  What is the reason for this?