"Imported" here only means that they crossed the border, not that they are being lawfully distributed in the US.
> Amazon and Newegg are US companies distributing imported Chinese Huawei phones.
Not true. Third party resellers are importing and selling some Huawei phones.
> ... show me where phones are banned.
Can you buy a Huawei phone from a retailer in the US? Amazon, Best Buy, Walmart? Or from a telecom? AT&T, Verizon, T-Mobile?
Huawei and ZTE have also both been banned from getting FCC licenses. You could definitely buy a Huawei phone in the US, but it wouldn't be licensed by the FCC.