"Unalived" might be a euphemism that's only necessary on certain social media to avoid censorship nowadays, but people were using the term "disappearing" (especially as a transitive verb) during Chile's Pinochet regime, if not earlier.

"Disappear" used in that way is not new. Unfortunately.

Unalive and disappear don't change the meaning of the thought, and they circumvent ideological restrictions that intent to restrict thought. This is opposite the effect of newspeak.