Rule 614.12 is only partially relevant to the original question. The important part is the one I quoted in my first reply, but it's (specially the bolded part and the example) just a direct consequence of rule 112.6 when applied to abilities that create replacement effects.
So to determine whether a particular ability works in a particular zone, we only need to look at rule 112.6. Most abilities from permanent cards only work while the card is already on the battlefield. However, there's a very small group of abilities from permanent cards that work as the permanent enters the battlefield. The ability from
Diregraf Ghoul is an example of the latter: it only works as Diregraf Ghoul enters the battlefield. The abilities from
Corpsejack Menace,
Orb of Dreams and Melira, however, only work on the battlefield. The ability from
Tatterkite is active on the battlefield but it also works as Tatterkite enters the battlefield.
Back to the original question: in this situation Corpsejack Menace's ability is not active yet, so it doesn't apply, and that's all.
The second part of rule 614.12 (
“To determine which replacement effects apply and how they apply, …”) tells how those replacements apply, but it doesn't really matter in this question. It's there because sometimes a replacement effect needs to
check the characteristics of a permanent as it enters the battlefield. Since at this very moment the permanent technically doesn't exist yet, we need to “predict the future”. Rule 614.12 just tells us how to do so.
So, rule 614.12 is relevant when it's not clear whether an ability of the permanent exists as it enters the battlefield. Also when the replacement effect applies only to permanents with a given characteristic, or when it applies in different ways depending on the characteristics of the permanent. It's not relevant at all when the replacement effect needs to check any other kind of info from the game state. In such cases we just look at the game state prior to the event.
Examples where rule 614.12 is relevant:
-
Bramblewood Paragon and
Conspiracy (naming Warrior) are already on the field.
Runeclaw Bear enters the battlefield. The bear spell is a warrior and the bear permanent will also be a warrior, but when we check to see if Paragon applies to it, we ignore Conspiracy, and the bear enters without a counter. However, if
Chameleon Colossus enters, the changeling ability is taken into account, so the colossus will enter with a counter.
-Sunburst is a keyword ability that applies to a permanent as it enters the battlefield. If the permanent enters as a creature, it gets +1/+1 counters, but if the permanent enters as a noncreature, it enters with charge counters. If
March of the Machines is on the field while
Heliophial enters, it will still enter with charge counters. If
Sculpting Steel enters as a copy of
Etched oracle, it will get +1/+1 counters.
To sum up:
Question:
Does this ability work from this zone? This question is answered by rule 112.6.
Question:
If this ability is working and creating a replacement effect that modifies how a permanent enters the battlefield, how does the effect check the characteristics of the permanent? This question is answered by rule 614.12.
Also, do note that Undying is not a replacement effect. It's a single, direct, unmodified instruction to put a permanent onto the battlefield with a counter. Normally, the effect from a resolving spell or ability instructs to put a permanent without counters and then another effect replaces the instruction to put a counter on the incoming permanent. Persist and undying, however, do all in one step, so nothing is replaced.