I think this is a good idea, however i think it should be a 'strongly suggested' thing, rather than forced. Perhaps a passenger lap in the instructors car could give the same idea on lines/braking points, but being a different car, the speeds/braking points will be a bit different.
I learned a lot from letting a trainer drive my car at my first PI sprint, showed me that my car was capable of going much faster than i was, made me feel more comfortable.
But like Chris said, if you're not comfortable with the WRX rules if they want to force this, you always have the option of doing Driver Training somewhere else before coming to WRX club.