Hub Replace:
We will be providing more detailed information in a separate post tomorrow, but the linked SDC presentation covers the feature well. With Hub Replace, you can now move all your Hub Connected devices and the configurations, routines, and other network information from one Hub to another. Another key functionality for this feature also includes Hub Replace support for Offline hubs. The functionality will roll out to all our Hubs with the 0.50.X release, and all Hubs (with some restrictions that will be highlighted separately in a separate post) will support this functionality. But in a simplified view, you can now replace any V2/V3/ST Station with another V2/V3/ST Station Hub. Hub Replace will also work for Family Hub, TVs, and Samsung Connect Home/SmartThings WiFi hubs, but some restrictions hold that will be highlighted separately.
Regarding the Hub Replace functionality support for offline Hubs: This will ONLY work if the offline Hub has 0.50 or newer firmware.
Let us know what additional questions you have.