Depends on the organization you're with. Marty Tyson has ALL of his girls from the top 12U on up teams in his organization get their hitting and fielding in with him. A friend of ours said that the best part of leaving that organization was them getting to go back to Jen for catching weekly instead of having to go to Marty.I don't know about the "mandatory" part. We haven't encountered that yet, but I have little doubt it happens with some teams.
Pretty sure that Stith had all or most of the girls in his organization fielding with him at STC and the catchers working with Mark before he passed.
Guess it comes down to what org you play for.