Just tested with a parrot and a wolf in 1.14.2-pre3. Both were ordered to sit, then I spawned a zombie in front of them, which attacked me. Neither of the animals stood up. Further testing in multiplayer is needed.
Still happening in 19w12b. My parrots always get killed in stupid ways because of them flying towards the creepers I'm fighting.
This still happens in both 1.13.2 and in the 1.14 snapshots. Being such an old bug it baffles me that there's still no response from devs.
Ezrovernum
Just tested with a parrot and a wolf in 1.14.2-pre3. Both were ordered to sit, then I spawned a zombie in front of them, which attacked me. Neither of the animals stood up. Further testing in multiplayer is needed.