@LightningBolt
Because of the episode where the CMC use a love potion to make Big Mac and Cheerlie fall in love with each other.
In the episode, it mentions that two Kingdoms were destroyed when a stallion (largely believed to be King Sombra) gave the love potion to the mare of his dreams (largely believed to be Chrysalis).
The end result was both of their Kingdoms were destroyed.
The theory suggests that it’s talking about the fall of the Crystal Empire and, if you go on the Changedling look being their original look, the decent of both Chrysalis and the Changeling Kingdom into love vampires.
Support for the theory of the Changedling look also comes from the AU in that one IDW comic story arc where, in one timeline, Chrysalis is actually good.
Her good self doesn’t even look like the Chrysalis we know, whereas Sombra from said AU looks like IDW’s pre-evil Sombra.. Leading some to both speculate and question the origins of the regular universe Queen Chrysalis.
None of this actually proves she’s not q changeling though. If anything, it supports the theory that the Changedling look was the original look prior to corruption.