Apple: Updates to the StoreKit External Purchase Link Entitlement

Developers can communicate and promote offers for purchases available at a destination of their choice. The destination can be an alternative app marketplace, another app, or a website, and it can be accessed outside the app or via a web view that appears in the app.

And:

Developers may design and execute within their apps the communication and promotion of offers. This includes providing information about prices of subscriptions or any other offer available both within or outside the app, and providing explanations or instructions about how to subscribe to offers outside the application.

Software providers (in the EU) will be allowed to tell their users how to sign up for services to deliver the best experience to their customers. What a concept!