The headline is misleading. The cited source in the article only talks about the included charging cable and not what limitations the phone has. A more accurate headline would be "iPhone 15 to Ship with USB 2.0-Speed USB-C Cables".
All USB-C charging cables that come with phones and laptops have USB 2.0 data transfer speeds. That includes flagship Samsung phones.
All USB-C charging cables that come with phones and laptops have USB 2.0 data transfer speeds. That includes flagship Samsung phones.