Yes, 2001 audio still has them and has them in stock in many GTA stores.
There is also the issue that Cisco is completely out of the TV set top box business. And so if you are buying a nextbox 3 digital terminal or PVR, you are either getting old stock, or refurbished.
Don't know about the Nextbox 4K who produces it, and whether new product is in the distribution line.
2001 audio sells the Rogers branded 4K boxes only. They don't say whether they are new. I suspect if anyone wants earlier boxes, it will be through the refurbished and Kijiji markets.