For a nice friendly video (which was on that page but now isn’t any more) showing how to enable it, and what’s new, there’s this link: video guide. To get an overview of what’s new Microsoft have provided this page. It doesn’t break them, and most of the confusing user prompts are no longer needed. As an example, if you amend a long-established recurring meeting Outlook can now update it, leaving historical meetings alone, but allowing future meetings to have revised attendees/dates/times. There are some minor improvements, but they take the form of more intelligent handling of things like amended meetings, with fewer confusing dialogue boxes needing an answer. The intention is that this is just an improvement – there should be no glaringly-obvious user-noticeable changes beyond snappier performance. These improvements are gradually being made available for Outlook-on-the-web (a.k.a OWA), Outlook for Mac and mobile (it’s already rolled out for these two) and, finally, for Outlook on Windows.
The Microsoft Exchange team have announced that an update to shared calendar notifications is now leaving preview and entering production.