Repositioning the pivot would be within the scope of awkward things that professionals grit their teeth and live with, but probably daunting for new users.
If you make that ear a named group it will save a custom pivot point (although there were some older versions where that didn't work). If the pivot point was getting left behind you could reset it quickly by unselecting the group, then re selecting it in the PWS.
I'm not sure what happens to a custom pivot point after some muscle mode animation has been done. My own preference for a floppy ear would be to rig it with a bone rather than use muscle mode animation, but the author may be using this as a sample case to introduce the concept of muscle mode animation.