I've been downgraded by UA twice in the past year and got just the confirmable upgrade - no drink or headset coupons. But I do recall the "downgrade packet" from years past, so wonder if this is a change, or should I be asking for the extras. Then again, I rarely drink and never watch the movie, so I got the one piece I do want - the upgrade certificate.
United even gave me a "downgrade upgrade" in April when my waitlist for first class had cleared but they changed aircraft...and never asked me for my (original) upgrade coupons. I thought that was real fair!