Of course this always depends on the product, but I typically like to think about use cases in addition to or in place of segmented audeinces. Use cases can frequently apply to a number of audiences and therefore better explain the value than just speaking to an audience.
Additionally, uses cases enable me to tell user stories that are much more compelling in trying to understand the "why" of a new feature or major release.
Ideally, it's a combination of the GM, product management and product marketing. The GM would set the overall business goals for the year or quarter including revenue. The PM often drives the product launch adoption and revenue goals for that product. PMM often builds the plan with the metrics to help back into those goals.
The important thing is that if you see a gap, make sure that someone is owning all of these goals, otherwise, it will be meaningless to have launch metrics.
I think you’re asking if it’s behind a pay wall and not just a free product? If that’s the case, you need material (video!) that can act as a demo, people want to see product, not just read about it. Salespeople who can give great demos and free trials are often a really effective a launch tool.