I can't imagine why it would break the parenting, unless you copied and pasted something you shouldn't. I use the technique all the time.

Didn't have any wings handy to test this, so I parented one of my posable tail figures to Posette, created a 30-frame wag cycle, then selected its Side-Side dial from the animation palette and pasted it five times to have it wag repeatedly over a six-second period.