Apple releases the newest watchOS update beta with legacy apps alert
Well, we shouldn't exactly call them new features, because chief among the newcomers is simply a pop-up warning that older apps will start working with unspecified future versions of the system, probably watchOS 5. The alert states that "This app will not work with future versions of watchOS. The developer of this app needs to update it to improve its compatibility."
This dovetails with Apple's requirement, made official at the beginning of April, that all new apps should now be made with later watchOS versions in mind, chiefly meaning that they should be made to operate independent of any iPhone connection.