"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
Apple Adding Late 2012 iMacs to Vintage and Obsolete Products Pilot Program at End of January
Vintage and obsolete products are typically no longer eligible for repairs or replacement parts from Apple or Apple Authorized Service Providers, but the memo states Late 2012 model iMacs will be eligible for Apple's pilot program that will permit extended service through January 30, 2021 worldwide, subject to parts availability.
Other products in the pilot program include the iPhone 4S, iPhone 5, Mid 2012 models of the MacBook Air and Mac Pro, and Mid 2012 to Early 2013 models of the MacBook Pro. The program began in January 2018 and was expanded in August.
Vintage products are those that have not been manufactured for more than five years, according to Apple.