I believe it was simply a low priority to Bioware, they weren't game breaking and so they stayed to maybe be fixed post release.
You only have to look at the facial animations in other games that use the Frostbite 3 engine. Bioware's own Dragon Age: Inquisition, while suffering from the same botox faces, didn't have half the issues that Andromeda has. Hell jump to Dice's first person shooters, where the animation on characters is light years above what has been made here.
One of the reasons given for moving all EA studios to the Frostbite engine was that it would make it easier for them to collaborate and help each other out. Well that clearly hasn't happened.