Should i have inapp purchases?

I have an app regarding a newspaper, the user has a lot of free articles to read. But now, i want to have some exclusive articles and a section where the user can see the weekly newspaper released.
Also, the app exists on Android and there is a web site where the user can see the same things on the app and can subscribe to see the exclusive articles and the weekly newspaper.

The question is, can i have the exclusive articles and the newspaper on the app? For example, when the user enters a exclusive article it will see a screen saying: Premium content. Just that, with no external links/buttons.

The guidelines say:

If you want to unlock features or functionality within your app, (by way of example: subscriptions, in-game currencies, game levels, access to premium content, or unlocking a full version), you must use in-app purchase.

I don't want to unlock anything through the app, but only on the website. If the user subscribes from the website, he will have access to everything on the app. If not it will appear the simple premium screen.

.3 Other Purchase Methods: The following apps may use purchase methods other than in-app purchase. Apps in this section cannot, either within the app or through communications sent to points of contact obtained from account registration within the app (like email or text), encourage users to use a purchasing method other than in-app purchase.

I think my app is included on this section.

Multiplatform Services: Apps that operate across multiple platforms may allow users to access content, subscriptions, or features they have acquired in your app on other platforms or your web site, including consumable items in multi-platform games, provided those items are also available as in-app purchases within the app.

This one is confusing, but my app is multiplatform and i want the users to have access to the content that they bought on the website.

.3(a) “Reader” Apps: Apps may allow a user to access previously purchased content or content subscriptions (specifically: magazines, newspapers, books, audio, music, and video). Reader apps may offer account creation for free tiers, and account management functionality for existing customers.

It's an app from a newspaper, so i think the app is included also on this category.

Can someone help me to understand if i really need to implement inapp purchases?