Valve has informed developers that it's 'running a little behind' when it comes to approving pre-release game build submissions due to the high number of re-reviews required, with some submissions taking up to 12 business days, compared to the usual 3-5 days.
To remedy this, Valve has updated its documentation on release checklists, requiring developers to double-check certain aspects before submitting their game builds, including running the game through Steam for at least five minutes, specifying common redistributables, and ensuring achievements and Steam Cloud saves work properly.