Over the past month, I've had several CPUs/GPUs clear without any email notification. Same goes for schedule changes. I had one schedule change that had me getting to my destination 24 hours later without any notification at all. I happened to notice it when reviewing my reservations on the website.
Meanwhile, UA has found a way to flood my inbox on the day of travel. I get flight reminders @ T-2 hr; then another email when my flight starts to board. One time, I even got one telling me what my connecting gate was and how long it takes to walk there. Unless there's a delay/IRROPS situation, I don't really find any of those to be all that useful.
I'd much rather get emails on changes to my reservation (especially those not initiated by me, like schedule changes or upgrades clearing), rather than a bunch of them essentially telling me that my flight is leaving on time.