While it nicely describes how to pull in updates to open-saas, it doesn't take into account that Wasp version might change, and that pulling in the updates might not be as simple as just resolving the conflicts. They should instead check if there are breaking changes in Wasp version, and if so, be aware of what they need to do in order to migrate.
In general, I wonder how often will people be updating open saas in this way, I don't think they will do it a lot since it is a project starter. Anyway it will probably become quite different pretty quickly from the initial code, so if they will want to do some updating, they should instead probably manually look at the new code and see what they can cherry pick.
So I would consider just removing this section. We can potentially put it in a separate section in docs, or completely remove it.