For german models wireless charging was introduced with the roadster and is a standard feature named "Telefonie mit Wireless charging"
Whyever it was never available for the Coupe. The option for the Coupe was named "Komforttelefonie mit erweiterter Smartphone-Anbindung" doesn't provide wireless charging.
Interestingly you can still configure the i8 on
bmwusa.com
But I haven't found a description of wireless charging and it's also not listed under Standard features.