Hello,
In my understanding, the CA API Portal is focusing on "publishing APIs" rather than being a general-purpose Portal software. CA API Portal 3.x has a built-in CMS for publishing documents but it is externalized in CA API Portal 4.x as "BYOCMS" (Bring your own CMS).
I'm not aware of the future enhancements in the CA API Portal 4.x but you can post your expectations for the product as Ideas in this community.
Best regards,
Seiji