Whoever owns the dominant platform have the power.
> When Spotify later submitted an app update with features unrelated to audiobooks, Apple rejected it. App Store reviewers told Spotify that the audiobooks offering, which had previously been approved, violated rules requiring apps to use Apple’s payment system to unlock new features, according to Spotify.
> Mr. Zicherman’s team changed the email customers would receive, stripping out the purchase button they had previously included. They replaced it with an email that gave customers a link to browse Spotify’s audiobook titles.
> Apple rejected Spotify’s change days later, saying that offering customers a button to receive an email about other purchase options broke App Store rules. An Apple spokesman said that Spotify also had a discrepancy in an external link in its app, which sent people to a different web address than one that Apple had approved. Spotify said the link was unrelated to audiobooks and that it has resolved that issue.
> Mr. Zicherman said his team consulted with Spotify’s legal staff before deciding to strip out the email phase of the audiobook process. In its place, they told listeners to go to Spotify’s website to buy a book.
> “What we have now is effectively a dead end,” Mr. Zicherman said.
> On Monday, Spotify said that Apple had rejected Mr. Zicherman’s latest redesign. He and a team of product designers, engineers and attorneys worked until early Tuesday morning on four other options. They stripped away Spotify’s website and directions for more information about audiobooks, putting the onus on customers to go online and figure out how to complete a purchase. The changes won Apple’s approval, Spotify said.
> “You can’t buy audiobooks in the app,” the landing page now says. “We know, it’s not ideal.”
Seems like Spotify wanted to sell their audiobooks without giving Apple their standard cut via some weird email linking scheme.
The wording seems deliberately ambiguous to give the impression that Apple is denying them for some unclear reason. Which they'd be very silly to try to do.
It's a lot more sensible that they're not willing to grant Spotify a carve out to their most well publicized and discussed rule regarding in-app transactions.
https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CEL...