Update: Microsoft is not yet releasing the Office 2021 for Windows or Mac products. It also is releasing its first Office 2021 for Mac preview - which it says is also for larger business and government customers. Microsoft is delivering a first public preview of its Office Long Term Servicing Channel (LTSC) release, the successor to Office 2019, designed for larger businesses and government users. Microsoft is making available today, April 22, the first preview releases of a couple of its promised next-generation 'perpetual' (non-subscription) Office client products.