"content" is actually well defined in the App Store terms. And it doesn't include SaaS under it.
Here is "content" being used to mean "everything that's in an app":
"The Application Provider of each Third-Party Product is solely responsible for that Third-Party Product, the content therein, any warranties to the extent that such warranties have not been disclaimed, and any claims that you or any other party may have relating to that Third-Party Product."
And here is the section on subscriptions, in which content is, in my opinion, not well defined:
"Certain App Store Products may include functionality that enables you to purchase content on a subscription basis (“Paid Subscriptions”)."
I just scanned all 72 mentions of the word 'content' and couldn't find the definition you're alluding to.
And lo & behold, I give you Section 11.13: "Apps can read or play approved content (magazines, newspapers, books, audio, music, video) that is sold outside of the app"... yadda, yadda.
Sounds like a definition of "content" to me...
Content subscriptions are timed releases of packaged, curated content pushed to you on a regular schedule.
Saas is a portal that lets you access data, information and tools on an ad hoc basis.