The Mazda 7 pin harness and hitch was once definitely available here in the US--I had my dealer order both for me when I bought the car back in May, because I wanted to roll the cost into the vehicle purchase and they also gave me a special price as a result. It took ~3 weeks to receive them. The OEM accessory listing showing projected release dates also shows them both as "early May" and that means 2022. I'm assuming that the initial production run was sold out and it is taking longer to have more available, so that's why online dealers show it active as being orderable. Maybe try calling the parts department of the specific dealer you purchased your vehicle from? BTW at least the 7 pin harness (but I'd assume the same is true for the 4) is labeled as a Curt product.