In order to do a superlative job as a manager of a software engineering team, one has to master these same skills. Perhaps the term "Software Scientist" will help distinguish good software engineering management practices from bad ones, but I fail to see how "The Software Scientist" is not a management role.
The only way that the post makes sense to me is that if the organization is large enough, have a role that supports CTO / VPE's efforts and tried to do it in a more data-driven way.
So this way CTO / VPE still have those responsibilities, but have a person who is fully focused on measuring the impact of changes and getting data.
I think these would be very special roles and very few organizations, so not enough to really talk about it as an alternative to the two traditional tracks. That said, there is certainly there is value in this role.