Rather than “they had trouble getting it to work”… my bet it was more… “OMG, we have so much to get done, forget this, get this done instead…”
It’s not like there’s much difficulty in getting animations to work. Except for the time it takes to do it.
Not to mention there are rumors multiple developers developed the default aircraft. It’s possible they may have had difficulty developing a standard animation procedure for all developers to use, so shelved it. And when I say difficulty, they spec’d out how long such a task would take and said “Nah”