One of the features of the HomePod is its ability to daisy chain with another HomePod, resulting in a stereo set of speakers. However this functionality has yet to be included as it is basically waiting on AirPlay 2 to be ready in order for this to work. It was expected that AirPlay 2 would arrive in iOS 11.3, but it doesn’t seem to be the case anymore.
It has been spotted that in the latest released of the iOS 11.3 and tvOS 11.3 beta that Apple has removed AirPlay 2 from either software. This seems to suggest that AirPlay 2 might only be released at a later date, possibly alongside iOS 12 which is scheduled for the later part of the year alongside the new iPhones.
This is certainly not good news for HomePod owners who might have been looking forward to multi-room or stereo pairing support, and only seems to reaffirm what a former Apple engineer said, which is that Apple has a work culture in which the priority for features gets shifted around quite a bit, sometimes resulting in features that face extended delays despite having been announced much earlier.
However an alternate possibility is that it could be that Apple would much rather delay the feature and focus on quality and stability rather than rush out something that doesn’t work. Either way we guess if you are hoping for those HomePod features with AirPlay 2, be prepared to wait.