I just received a reply from Steinberg support, sadly, confirming that the MR816 series interfaces are discontinued (no longer being made). Well done Steinberg. Do you realize that you have wrecked any usefulness of the Control Room feature in Cubase? As far as I know, the MR816 interfaces are only ones that allow you to use the Cue Sends in the Control Room with Zero Latency monitoring. This is the single most important part of the Control Room. Without Zero Latency monitoring, the Control Room is of little or no use!
To add insult to injury, Steinberg is selling off the reaming stock at full retail price. I’ve never seen a manufacturer selling off discontinued products at full retail before!