The full message he received on August 28 from Microsoft:
"We're currently upgrading Outlook.com accounts. During the upgrade, you won't be able to share your calendar with some accounts, but you can still send a link to your calendar by clicking 'Get a link.' We expect the upgrade to be finished in the first half of 2017. We apologize for the inconvenience and thank you for using Outlook.com."
By making Outlook.com more like Outlook, Microsoft execs said they'd bring a host of new capabilities to Outlook.com, including support for "Clutter" for de-cluttering inboxes; mail themes; automatic link preview generation; pop-out read and compose windows; support for add-ins like Uber, PayPal, and Maps, and more. Suggested contacts and automatic flight notifications would become part of the Outlook.com feature set, too.
The existing Outlook.com service was running on a legacy infrastructure. The new Outlook.com is using "the same building blocks as the rest of Office 365," The result will be that new features can more quickly and easily be introduced across both Outlook/Office 365 and Outlook.com, moving forward, rather than building twice for two different platforms.
I asked Microsoft officials again today, August 28, for an update on the Outlook.com migration timetable. No word back yet. I will update this post if and when I hear back.
Update (August 29): A Microsoft spokesperson said the date in the pop-up reported above was incorrect. But Microsoft officials are not willing to say what the correct date is or even how much after the end of August it is.
Here's the official statement, from that spokesperson:
"The error message incorrectly stated the date as the first half of 2017; we're updating this message to reflect the latest migration schedule. We are in the final stages of the Outlook.com migration, with nearly 90% of our active users already migrated. A small percentage of our active users will take additional time to migrate based on certain features they are using like shared calendars."
So we still don't know what "additional time" means, at this point....