They didn't even make 20 animations for *NEW* abilities for the whole healer role for DT's expac. What makes you think they would devote animation and coding resources for failure animations that you should not be seeing a majority of the time?
Unless they are minor animation tweeks where you lose your flashy effects, and not different failure animations like the two examples you gave, It's absolutely not worth their time. And even still, a new universal failure que would be preferable to reworking everything.
