That thing that happened with GChat / Hangouts / Google+: https://twitter.com/danluu/status/1504567918746431492.

More generally, all sorts of weird stuff getting tied to Google+, with threats to careers of people who didn't get in line: https://twitter.com/danluu/status/1122617702080581632

Similar story, but on the infra side, for a migration that probably doubled the server infra cost of a $100B+ company and caused a huge amount of re-write churn (this decision later flipped around and is now causing re-write churn the other direction).