I totally agree. The last update to "Changes" was over a month ago. Uh, lots of shiz has changed since then...

As the OP said, people are going to change their habits to reflect the changes one way or the other so it's not like you're stopping anything by not telling people, but they will be a lot less angry and feel less betrayed if they were made aware of the change BEFORE it happened.
Also maybe we could give some constructive feedback in such cases like "Uh 24 hours is way too drastic a change". Things of that nature.