Yeah, I'm not sure that's accurate. Call of Duty is listed, but the publisher has opted out of Backwards Compatibility program.
They haven't opted out of it at all.
That is just a list of games that MS are testing right now. That doesn't mean all of them will make it out to the public. For example they could just be testing the emulator on Red Dead because the code is a mess, even if they have no permission to release it to the public. Or in Activision's case, since we know talks are ongoing and positive according to Phil Spencer, they could just be testing it and getting ahead of the curve so that it's ready for launch, being the most voted game and all.
There's plenty of reasons they could be testing games internally so not all of them will come into the limelight, but it's a good list to go by to get a rough idea of what's to come.
Edit: The cod titles were on the list long ago, pre gamescom so they have been testing it for some time now.