"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
AT&T Shuts Down 2G Network and Ends Cellular Connectivity for Original iPhone
As The Verge points out, the end of the 2G network means the original first-generation iPhone (also known as the iPhone 2G) will no longer receive cellular service from the AT&T network, effectively shutting it down.
Few people appear to have been using the original iPhone as there were no complaints from iPhone owners two weeks ago when the network was shuttered, but going forward, customers who keep the device as part of a collection will only be able to use it on WiFi.
Originally released in June of 2007 and discontinued in 2008, the first iPhone was made obsolete by Apple back in 2013, and it has not received software updates since the 2009 release of iPhone OS 3, later renamed iOS 3.
While the end of the 2G network seems to have had little impact on iPhone owners, it did manage to cause significant issues for the San Francisco Muni bus and train system. NextMuni, used to predict arrival times of buses and trains, ran on AT&T's 2G network. Muni vehicles without upgraded systems installed don't show up on NextMuni, a problem that the San Francisco transit agency believes could take weeks to solve.
According to AT&T, shutting down its 2G network frees up valuable spectrum for future network technologies, including 5G. AT&T says the spectrum will be repurposed for LTE.