This one's no better, either, as Costco's terms for its wholesale suppliers aren't anywhere close to Apple's, even though the agreement is structured more or less similarly -- but sure, let's entertain it: Costco's terms for its suppliers aren't public, but at least the ones that are on public record (via the SEC: https://www.sec.gov/Archives/edgar/data/1940372/000149315222... ) make no restrictions on the choice of payment processors for digital products, which is what Apple got fined for.
There is a restriction on promotional material enclosed with the product (as in it needs prior written approval from Costco, not as in it's completely banned) and an explicit mention that it applies to digital products as well. But there is no requirement that digital products sold by Costco as merchant of sale for the supplier enable purchases only via Costco.