Resetting the standard I've not yet seen the article but, having represented NZISM on p45001, can respond to some of Dianne's comments.
AS/NZS4801 has not been reviewed or revised since 2001. It should have been in the roughly five yearly cycle of review/revision but escaped the attention of Standards Australia and Standards NZ. When ISO45001 has been adopted it is likely that Standards Australia and Standards NZ will ask what should happen to AS/NZS4801. Based on experience with other joint adoptions they will be asked to withdraw AS/NZS4801. BSI, ILO and other "owners" of OHSMS standards have indicated the same will happen to their standards, leaving us with an internationally written and jointly adopted standard with a review/revision cycle.
AS/NZS4801 (also an industry based standard) obviously was not developed by ISO using Annex SL as the framework and is not a management system standard (MSS) as defined by ISO. The gaps are especially evident in ISO45001 clause 4 - there is no equivalent in AS/NZS4801.
Even a cursory reading of ISO45001 and (say) ISO9001 shows their relationship and the opportunities for OHS practitioners/professionals to integrate an ISO45001 OHSMS seamlessly with other ISO MSS to the benefit of their organisation (less paperwork, etc).
ISO45001 was developed in a multi-party process that included unions, employers, OHS organisations (including IOSH) and others.
Nobody is required to implement it but, based on the Masterclasses I am running for NZISM, several hundred NZISM members have it in their medium to long term plans. The Masterclasses include how to include a gap analysis to help attendees see the big picture and not work inside an OHS silo.