With the return of AirPlay 2 in iOS 11.4, it appears that Apple still has some tricks up its sleeve. Readers and Redditors are reporting that the AirPort Express (the ‘latest’ model released in 2012) is showing up as a speaker accessory in the Home app.
This suggests the new AirPort Express will support AirPlay 2 to participate in features like multi-room playback alongside other speakers like the HomePod.