That helps, I'm remembering the semantics now. This isn't cannibalism as in 'conspecific predation', so yeah basically biologically fine. However treads on all the usual ethical topics of cannibalism though like not having a clearly better option, eating a sapient (bird)man, eating from a man-eating predator (like a tiger, boar, or something mythic like a dragon), AND eating honored kin.
So it falls between usual definitions of cannibalism but yeah, morally justified.
There's no end to that

If you include extra steps life is cannibal stardust.