I shall add it's funny they keep saying "Microsoft Loves Linux" but refuses to release any of their major desktop client software for Desktop Linux.
And for Office they would use browser version which works fine. It makes no sense for MS to invest resources into this since there isn't enough interest to justify the investment.
Honestly, if they were going to have a Linux client at this point, I would expect it to just be an Electron wrapper around the Office 365 webapps.