TS 16949 will NOT FOLLOW the HLS (high level structure).
My understanding is that the industry has chosen not to comment as an industry on 9001 or 14001, that is for the individual company to decide. Also, it is important to remember that ISO MSS are voluntary standards, an organization may choose to stay with 14001:2004 if it decides this is in its best interest.
I am providing here my own explanation of the message I have seen from the TMB. Annex SL is a "should-all', TMB would like all MSS to follow it, but understands the need for exceptions. Any deviation must include a rationale. It is not clear at the end of the day what TMB will do with these deviations. And, with your data on 13485, that makes TWO standards that will not follow the HLS. I expect there will be more.
In addition, there is some flexibility in how the HLS is applied - some versions I have seen will not make them user friendly documents, another ding in ISO's market. As it stands ISO has less than a 1% adoption globally against the stats for any MSS adoption when compared to the number of legally constituted employer-based entities in the world.
I don't think anyone would argue the logic and potential savings of a 'plug and play' approach where it enabled users of multiple standards, a simple framework on which to build an integrated system, whether it was for EMS, QMS, ENMS, or whatever. However, the extent to which those involved with drafting the HLS, in my personal view, went too far. In the 20 years of my involvement in writing and negotiating MS standards, and helping write guides for users and helping the development of EMS in entities, I have yet to have someone state that they could not integrate other ISO MS standards.
I had not heard about 13485, thanks for that data. Will investigate.