"Feedback week" is not an outcome I would leave to chance unless I trusted management to an extraordinary degree. Getting good feedback would become my priority for the week before and I would be forming partnerships with people to play up certain aspects, especially if management (the people who decide my paychecks) are going to be hearing it. Why would I do all this? It is very hard to shake a negative impression, so preventing one is imperative.
Feedback week tells me to spend the week before not asking for help which may be hard to provide, investing in colleague lunches, sending them job postings and encouraging them to seek a promotion, withholding cool productivity improvements until just before feedback week (I have this cool new automation script), and planning my feedback with close team members.
That seems like a worse outcome than having me actually doing work.