There will be two models available, two new RAID models available, one full height, the other low profile to be used in servers. The cards are based on a PCIe Gen 3.0 x8 connector. ... HighPoint adds SSD 6204 RAID controller that can hold four NVMe M.2 SSDs
The low profile seem nice to me. But i don't know about the quad one for sure RAID might have enough in X8, but for around 50 to 100 euro more depending on quality, you can have a card cabled in X16...
Sadly it doesn't work like that, it depend on the raid controler... But i agree that if the controler can use a x16 lane bandwith, it may more exploit the SSD at their full potential. And it's not expensive BTW