I don’t disagree that this is typical, I disagree that it is mandatory.
Dark Iron Dwarves were called this long before Ragnaros, were it mandatory that any changed group change their name, these would be known to us as something like “Furnace Dwarves”.
I thought that in that audio drama from Legion, they couldn’t (or didn’t, for some reason) make physical contact. I can’t remember the specifics, though.
The only canon thing we know is they live healthily into the 200’s. That’s ~3 times the lifespan you could expect from the average American, whose familial generations are typically in the 20-30 year range – if we cared to theorize, this might mean that a typical familiar generation for the Dwarves would be something like 60-90 years.
Which means that we’d be somewhere between ~1/6 and ~1/9th of the way through the generation which represents children born post-Ragnaros. In any case, there is only a singular example to go on at this point, and it’s Dagran Thaurissan II – who by all accounts was born post-Ragnaros and whom displays precisely none of the Dark Iron’s fiery traits.
As you’ve suggested, it’s certainly plausible that the Bronzebeard’s just have strong genetics – but as it’s been demonstrated a half-dozen times already, canonically, it’s more likely that in the absence of the catalyst (in this case, Ragnaros’ raw energy) successive generations simply aren’t affected by the maladies of their parents.
It could be, of course.
It still seems more prudent to tentatively accept the pattern as being intentional, with outliers being unintentional – because the alternative requires that one believe Blizzard has accidentally created a narrative wherein this pattern exists for such a prolific number of the races.
We just don’t know for Void Elves.
For DID’s, we’ve only got one example of someone born post-Ragnaros and that someone doesn’t present with any of the typical traits of a DID – though, in fairness, he’s only half-DID. We don’t know how that factors, but it’s entirely reasonable to expect him to have at least some of the DID’s traits – if they were heritable.
I’m not sure what you actually thought I’d bring up, but I don’t really think that we’ll be able to determine if Night Elves (or Nightborne) or High Elves (including BE’s and VE’s) fit the pattern I’ve described without Blizzard helping us out.
The only means we’ve got at our disposal to determine whether or not the pattern holds is looking at successive generations, who were raised absent of the catalytic magic, and none of Elfkind procreates enough for this to be something we can reasonably expect to see in-game – which means Blizzard is going to have to straight up tell us.
…but that would involve actually talking to the community.
At least we have Christie Golden. 
Same. I’m not sure how I would’ve handled it, because the obvious choices for Legion were Nightborne and Vrykul – which would have to both go Alliance, in order to not shatter the dichotomy I described above.
They might’ve been able to pull off:
- Nightborne (A)
- Vrykul (A)
- Void Elves (H)
- Nathanos-style Forsaken (H)
- HMT and LFD being unlockable customization options for Tauren and Draenei.
This would’ve also allowed the Void Elves to maintain their typical skin color, but to pick up on the WCII-era vibes without BE’s objecting to it – while also keeping the door open for playable High Elves in the future.
I’ve repeatedly intoned that I’d like to see High Elves be subjected to some heinous calamity, which alters their physiological appearance – so “game design” doesn’t factor, as it relates to any of my commentary specifically.
It’s stated in the presentation for “Storm Elves” that their skin color isn’t an issue, and you’ll never find a post in this thread from me asking for pink-fleshed options for Void Elves. You’re arguing with yourself, not anything I’ve requested. 
