Your choice. They can run a pool with high CYA as long as they run high chlorine levels per the Best Guess Chart. Or, they can do a few partial drains and refills. But do NOT totally drain the pool.

EDIT --- Just went back and looked at your original post to find out the volume of this pool. They have a big pool. That would be a lot of wasted water to do drains. Since they are planning on replacing the liner next year, I think I'd just live with the high CYA if it were my pool.