AMD are being absolutely full of it with this statement, in truth 8GB is UNACCEPTABLE in 2025 for the prices that they're charging, but putting all of that aside, just like Nvidia it's a predatory and scummy practice to have two different GPU's with the same name DON'T CALL IT THE XT!
If you persist with making an 8GB card separate it so that non tech savvy customers don't get ripped off by buying the compromised model.
They could have easily called the 16GB model the XTX as they've used that moniker already, there's NO excuse for not having a different name for the 8GB and 16 GB models.