Beats the old process of no challenge, and to be honest I'm not sure how I feel about it. You won the spot then in my eyes you have earned the right through the entirety of the season. The season begins the moment you win the spot and does not conclude until Olympic Team Trials scales open. It's both a perk and a heavy responsibility, nay duty, of being the world team rep.
Makes more sense to have them on weight a few weeks prior to the event they are challenging so they can decide to ramp up or taper down and adjust their OTT training schedule accordingly.