I'll guess that The unannounced: The return (Parade) is Trick R Treat. The riddle for the codename was It's all a round the season, in every possible way,
From sustenance to ambiance it hangs around each day. It's been said that it's not the sun, but looks like the sun and you can't eat the sun. It's been stated that it is tied to Horror Nights and October in general. I'm going take a guess that the codename is pumpkin. So, I believe Trick R Treat can fit with codename pumpkin. It's an IP and just because it's returning I don't believe you can assume the first time around was directly tied to the IP. They've used TRT before but only as inspired by an IP.
That being said, I'm actually putting TWD under The unannounced: The returning and Krampus under The unannounced: The expected. I'm doing that because I believe it fits with the consensus that we will get Krampus and also that we will most likely get TWD also.