Use case: a user is authenticated in an external SaaS application. He then needs to access a knowledgebase that should only be accessible for paying customers and not the general public. If this kb is hosted on Hubspot, then it should be possible to use a third-party authentication (using JWT, SAML, Oauth or other mechanism) to provide this user with a single-sign-on experience.
As it is right now, the user needs one set of credentials for the main SaaS application and then a second (and different!!) set of credentials to access a protected knowledgebase in Hubspot.