"Because shock value!" is an abysmally bad reason to write anything into a story. This isn't about it being a trope -- pretty much anything can be seen that way, as TV Tropes has proved, and I'm a card-carrying folklorist; I'm well aware of the value of a Motif Index -- but rather a trope which, at its core, is about devaluing and throwing away a powerful female character purely for shock and to motivate some man in her life. Deploying it here would be bad storytelling: it doesn't tell us anything about Aramoro we don't already know (we're already well aware that he's a murderous jerk), it doesn't meaningfully change Toturi's trajectory (he's already very thoroughly motivated, and will have plenty of reason to go after Aramoro), and it completely scraps Kaede's characterization, abilities, and agency, not to build anything narratively important in the longer term, but simply to surprise the players. Ned Stark's death worked because it added depth to the story, showing you that the bad guys were more vicious and petty than you'd realized, making it clear that ASOIAF was the kind of story in which honor pretty much just buys you an early grave, providing sufficient casus belli for the North to revolt, and decentralizing the plot so that his children could fully develop into protagonists in their own right, rather than him being the "main character" while others played supporting roles. All without in any way violating what we'd known about Ned up until that point -- in fact, it was more like a Greek tragedy, watching his greatest flaw (which was also his greatest strength) bring him down. He played as much of a role in creating his own demise as anybody else did, rather than being collateral damage in somebody else's plot.
None of that would be true here.
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