Alzurius said:
It's not like D&D is bound to having the game monster follow the mythological depiction of a creature; they have a long history of bastardizing monsters as it suits them.
And they have a recent history of bastardizing themselves when it suits them (arguably, that history is not so recent).
I think the design criteria for 5e (ie: a "big tent" where fans of every e are welcome)
mandates that they take into account the 4e devil-style succubus. You may question whether this is or is not the right criteria to design for (I tend to think it's a pretty good call), but given that constraint, 5e cannot retcon the 4e devil-style succubus, regardless of the reasons they may have for doing so. Rename, recategorize, re-explain, re-contextualize (what I wouldn't give to see one of these Wyatt columns talk about what DMs can do to adapt their monsters to their OWN games, instead of laying down some absurd new canon!), but it needs to be a part of 5e, if 5e is to be a system that welcomes all comers.
Given that constraint, I wonder what may be some alternative ways that one could work to satisfy each camp. I think Wyatt's proposition isn't bad (it just ignores DM agency in favor of laying down What Is True In D&D, which is a bigger problem than Wyatt). I can think of a few other ways it can be done (admittedly, I'm not familiar with the fiction Wyatt lists as part of the canon that he feels inclined to adhere to, so this may violate that).
- Succubi are demons who love to destroy the world with sexuality. Erinyes are devils who tempt mortals into acts of depravity of all sorts. A succubus comes into town and leaves a syphilitic plague behind her. An erinyes comes to town, and suddenly the local king gets a lot more...forceful.
- Succubi might be demons or devils. Here's an example of what a demon-succubus might be. Here's an example of what a devil-succubus might be. This is an example of how you can define your campaign's tone with a simple change. The PC's do not know which side a succubi might be on unless you tell them.
- Succubi are yugoloths, known to work for both sides. They have been part of the Demonic hordes, and have been part of the Devil's heirarchy, each side utterly convinced that their side represented the TRUE nature of the succubus. The true nature of the succubus is actually mystery, deception, and untruth, which actually fits with yugoloths. This may or may not be known to people in your campaign world: they may think the succubi might be demons, or devils, or neither, and perhaps as far as that world is concerned, this is true enough. One should not put much stake in such knowledge, though.
- Succubi are the offspring of Hags, specifically Night Hags, and as such are actually fey creatures, not fiends at all. As the Night Hag is a hunter of dreams, so is the succubus, literally the woman of your dreams made real. The hags have placed succubi networks in both demonic and devilsh ranks, but the hags are their true mothers, and succubi who do well may be promoted to Night Hag status, abandoning any pretense of Law or Chaos and embracing their own selfish path to power.
Some of those ideas are probably untenable for other reasons, but "Ignore 4e Devil Succubi" isn't an option that 5e has.
The big thing is, the borders of "succubus" need to expand. It can include the destructive-lust succubus that you and I favor, those succubi are part of the model still. They just aren't the ONLY part of that anymore. It's a bigger tent, because the designers have determined that embracing 4e fans is more important to them than strictly defining the succubus as one specific kind of fiend only. I can't really fault them for that choice.