>"Arcane language" 
  >"native" code that react native is generating for the animations.
  >CSS as an animation engine is completely acceptable, and it's limitation
  >TFA

No way that pun is intended, but CSS is kinda a Tunable/Timed Finite Automaton; but being of a lower class of technically-capable expression than Javacscript, which is of a higher set of class of automata.