Couldn't find this via searching this (very long) thread. Apologies if covered elsewhere.
Imagine I'm a 1K traveling with a 1P on the same PNR. I know I can do a same-day confirmed change to a different flight for no fee, but because of the same PNR situation, does that mean both of us have to change, and I have to pay said fee (or the standby fee) for the 1P?