I wrote the original trope years ago, before I had any idea what a "Snowclone" was. I'm not sure what the problem is; it was once considered okay to have tropes that have similar names as other tropes, if it helps explain them.
Why is this difficult to understand? Deus ex Machina
is a trope where the day is saved suddenly and arbitrarally by an unexpected source. Dead ex Machina
is a sub-trope of that, when a dead person, or person previously thought dead, saves the day unexpectedly. This is a thing that happens in literature. Does it have to be popular to live on the wiki? Would "Spiritus Ex Machina" be a better name? It's not always a spirit that saves the day. Is maintaining Latin continuity that important?
I can see now that somebody really mangled the first paragraph, though. I'm obviously biased, but I think the trope could use some re-writing for clarity, though.
"The secret we should never let the gamemasters know is that they don't need any rules." - E. Gary Gygax