research/creating/promoting don't really fall under an SEO title. If search engine optimization is broadly defined enough to where content creation is considered SEO, then basically everyone with a website is an SEOer.
Content marketing is certainly rooted in SEO though, with the often-existing explicit intention of having a relevant piece of content rank well for informational queries. Or at least having this content designed to attract links, which are still a major part of the ranking equation.
The lines are definitely blurring, so the main thing I'm arguing is that SEO should be in every marketer's tool belt, it's not some black hat wizardry anymore.
Everything on the internet is rooted in SEO, by design. Google has the intent that truly fascinating things be given the most visibility on the internet, that has nothing to do with studying up how to appear at the top of google's list and everything to do with studying how to be fascinating to people on the internet.
SEO is constantly evolving. Table stakes is a website that is easily indexed. SEO strategy is currently focused largely on creating and promoting content.
The lines are definitely blurring, so the main thing I'm arguing is that SEO should be in every marketer's tool belt, it's not some black hat wizardry anymore.