xFi Complete customers now have faster upload speeds

https://www.xfinity.com/hub/internet/faster-upload-speeds

This page says the following:

Exciting news! Now, eligible xFi Complete customers can receive up to 5–10x faster upload speeds. This is just one step toward providing our customers with next-generation Internet speeds.

Our existing upload speeds give you plenty of what you need to upload files, video chat, and game online. So, what’s the benefit of faster upload speeds? You can do more of what you love.

Plus, as an xFi Complete customer, you’ve got more than just faster upload speeds. In fact, you can enjoy tons of great benefits:

I have called and chatted and no one at Xfinity seems to know or believe that this exists. I had one CS agent say I needed XB8 modem to get these speeds (after spending over 30 minutes convincing her it existed), but they sent an XB7 modem (which I already have).

Does anyone know if it is real and how to actually get the faster upload speeds?