FlyingChihuahua
Hero
Its called catering to the homebrew. As DMs develop their world, they fill in their own blanks and change things to fit their idea of how the game should work, and then get really upset when the rules contradict their well-rationed and extensively researched homebrewed setting. This get exasperated with edition changes and suddenly (for example) dwarves can be wizards (which contradicts 7000 years of history in my homebrewed world, including the cause of several major wars). As the rules develop (and move away from the defined lore of the homebrew) the reflexive action is then to wish the game rules were "less flavorful" or "flavored like they were previously" and turn the game towards a toolkit of generic fantasy rules that can be used to assemble their homebrew games rather than contradicting their ideas on races, magic, gods, and a host of other topics..
Kinda off topic from the current discussion, but I do feel like you could do something with the "dwarves suddenly gaining magic" thing. Like maybe the sorcerous dwarves could be in hiding or something like that, because they fear that if their talents were discovered that they would be captured and experimented on.
I dunno, just an idea that maybe doesn't even work in your world because magic just straight up doesn't work there, I'm just trying to say that, within changes, there is opportunity.