So, I kinda hate myself right now (only partly kidding) · 4:08am Sep 6th, 2017
As I was walking home from the bus stop this evening, my thoughts eventually drifted toward "To Change a Changeling," and from there to contrasting Changeling behaviors and presumed needs under the leadership of Chrysalis and Thorax. I then fixated on why the new!Changelings seem to be able to get by just fine without the external sources of love they needed in their old forms. "Has more changed than just their looks?" I asked.
"Perhaps," I answered myself, "they were simply incomplete. Not fully transformed before, and unable to properly process love and thus constantly hungry for it."
The next connection I made I blame entirely on the fact that I've just started revisiting Brandon Sanderson's Cosmere novels. In fact, I just finished Elantris a couple days ago, so that whole system's pretty fresh in my mind.
"Oh my gosh!" I exclaimed, nearly throwing my hat on the ground, "Changelings are Elantrians!"
(if you don't understand the logic behind this connection, read Elantris. I'd rather not spoil the main twist of a great book.)
And so now I find myself with rock solid link from which I could start crafting Pony adaptations of Cosmere novels. 
As if I don't already have enough writing projects to work on.
Headcanon accepted! Headcanon accepted with extreme prejudice!
(And no, the fact that this dovetails together my two favorite fantasy universes doesn't bias me at all here. Nope.)
Edit: they may also have a similarity to Roshar's surgebinders, given how their transformation comes after having committed themselves to an ideal. Of course, I'm also a fan of the thought that Equestria's loosey-goosey magic/physics is because their spren have a sense of humor.
Likely that with dark throne that was keeping Badlands a wasteland, they couldn't live in there another way. Not that it matters whether or not everything is as it seems, Chrysalis must be keeping some deeper secrets still. She might prove it wrong.