No, there is no such thing as a downhill Redan because the ground game aspect of the design is compromised - its a different sort of hole. Part of being uphill is that the grounder is encouraged and seen as viable alternative. Remember, a Redan is like a fortress and it isn't very clever to build your fortress in a valley. Though, I could see folks trying to learn how to hit skinnied fade!
Perhaps the true concept of a Redan is not adhered to because folks don't tend to like uphill (or perhaps even the appearance) par 3s. This is understandable especially if there is an obscured view of the green.
Ciao
Sean,
I like uphilll Redans better than downhill, for sure. But remember, the original hole was NOT built to resemble a defensive fortress! The hole was built, including a wooden-slatted wall, and then some retired British officer made a remark while playing at North Berwick that the hole reminded him of the Redan at Sevatopol where he fought the Russians....
So an uphill Redan is just a better copy of the "original." A downhill version is just that: a downhill Redan.