There are many ways to deload people. You can deload by dropping DE work, dropping the volume, dropping the ME work.
That being said, OP, if you're deloading by keeping the heavy stuff in, that should be the only thing you do that week, no accessory or anything else. Personally I like dropping ME work for deloads to give the joints a bit of a break and I move my stance significantly in for squats that week to give the hips a rest.
Give the program a try, it may work, it may not. It's nothing special, just a basic linear periodization, which has been proven by many that it works.