Predictions for 2019:
Microsoft buys large stake in Canonical and an even bigger partnership forms
Canonical IPOs and the stock does exceedingly well
Microsoft releases either Exchange or SharePoint for Linux. Most likely in a container of some sort. Probably Kubernetes they open source it, a Snap if they don't.
Microsoft releases more stuff using Electron, including one BIG app, such as the base office suite (Excel, Word, PowerPoint, Outlook), most likely mirroring their cloud versions.