I may be off base, but it's my understanding that the 1.2 or 1.3 HDMI spec is only for the amount of data it can send, not that it will decode a RAW 1bit stream. There is nothing I have seen on the receiver you noted that says it is capable of doing this, only that it is capable of receiving that much data...in other words I see no mention of 1bit data, DSD, or SACD. I would be shocked if you just happened to purchase a receiver with 1bit capabilities without specifically looking, they are pretty rare and usually have Sony written on them.
That said you will likely be more than happy just using the 5.1 analog outs on the OPPO, and, well, going analog...that is how the majority of folks I know listen to DSD/SACD including myself.