We are at that difficult moment for some applications that we find available in wearables and let me explain. Keeping an application available on wrist devices is something that requires time and work, if this time and work invested is not remunerated in any way or provides interesting options for developers who have little future. In this case we are facing a series of applications that have disappeared from one day to the next without any mention, Target, eBay, Amazon or Google Maps are no longer available on the Apple Watch and no one had noticed ...
Obviously from Apple they are not going to explain reasons since it is not something that Cupertino's have to do, it is rather a matter of the developers. In this case from Google Maps they have already warned that they will have their version available again on the Apple Watch soon, but the rest there is no data if they will be operational again in the Apple device in the short term.
Those in charge of revealing this news Apple Insider They also have no explanation or apparent reason on which to base the output of these applications from the Apple Watch, but it is possible that the notifications of both applications are not enough reason to continue with the support on the device and this added to the more than possible little interest of users - since no one complained about their departure from the clock and we do not know when they are not available - makes developers choose to stop having these applications available. We are not facing a complicated situation of Apple's smartwatch or a failure for any reason that requires removing those appsIt just seems that we are facing the maturity of the applications for the Apple Watch.