Oneiroi Series/WMG

All the stories Water Smurf has written are in the same continuity.
Yep, the Snarl'd world is both a wasteland and Silent Hill. And Vaarsuvius has something going on with Belkar and Redcloak. And somehow it ends up with everyone with amnesia in a boarding school somewhere.

No, but in all seriousness, Dumped on the Rooster is probably part of the Oneiroi. Why else would Greek myths be such a heavy theme there? (Except for, you know, the obvious reason.)

In Dumped in the Rooster, the characters are trapped in a Lotus Eater Machine.
There are only a couple characters in there, probably V and Redcloak, and everyone else are just made by their minds.
 * Maybe they're still soulbound by Xykon and the boarding school/Greek deities scenario is just them going completely nuts.

All of the weird women coming after Vaarsuvius and Redcloak in Dot R represent Deirdre and/or Tiasal.
The world is made by their minds and the desire to escape the pain and guilt she caused, but they know that they can't hide from it forever, so they imagined women alternating between a small child and grown beautiful girls to bring them out of the dream.

In Dot R, the whole world's been eaten by the Snarl
Hey, we don't know what getting eaten by the Snarl is like. Maybe the mortal world's been eaten, and that's why they're hanging with the Western Gods, and so have all the afterlives, and that's why there are dead characters around.
 * Subtheory: And it's all Redcloak's fault, which is why he's so screwed up when he remembers in the flashbacks.
 * Subsubtheory: It's partially Redcloak's fault but Xykon was involved and he somehow got destroyed, which is why he hasn't appeared yet.

Deirdre's daughter is going to be born and be even worse than her mother.
She's a little demon child Deirdre keeps ranting about, so it makes sense.

Dumped on the Rooster will have a Downer Ending.
Most of Water-Smurf's stories have Downer Endings, and Dumped on the Rooster is dark to begin with. Not to mention that if all of Water-Smurf's stories are in the same continuity, DOTR almost positively comes after the Deirdre Ending, which exemplifies the Downer Ending trope.

In Dumped on the Rooster, the water bottles at the school contain diluted water from the Lethe, while the apples contain a counteragent.
The water has the same but less powerful effect as the water from the Lethe. Both waters remove the past memories. The Lethe is more forceful and requires only a touch, while the water bottles need to be drunk before they take effect. The apples restore memories, as seen in the many instances where a character almost eats one.

In Dumped on the Rooster, all of the Afterlives have been destroyed, so everyone is being reincarnated.
In Requiem Angelō Damnatae, the Afterlives are being destroyed, which shows that they can be destroyed, even if all of Water-Smurf's stories are not part of the same continuity. Since there is no other place for everyone to go, they get reincarnated into the world continuously.
 * Subtheory: Each of the apple trees in the orchard represents a past life. In Dumped on the Rooster, the woman with the snake- likely Hecate, or a representation of her- says, "I remember back when there was only one tree in this whole place." The apples restore memories, so over time more apples may be necessary as the number of past memories accumulates.