That just means that, with your motherboard, if you use an M.2 drive, NVMe- then one of your SATAIII ports will not work, that's just because it's using that channel that was once for a SATA port, for your NVMe. And, that's completely fine, unless you intended to fill every single SATA port with a drive of some sort. NVMe is faster than nearly all SSDs anyhow, so the loss of a SATA port is minimal when using a 32gb/s drive.