MacRumors published a story that Apple has released the first beta of watchOS 10 to registered developers.
Apple Seeds First Beta of watchOS 10 to Developers
Following this morning's keynote event, Apple has seeded the first beta of an upcoming watchOS 10 update to developers for testing purposes.
Apple Seeds First Beta of watchOS 10 to Developers
To install the βwatchOS 10β update, developers will need to open the Apple Watch app, go to the Software Update section under "General" in Settings, and toggle on the βwatchOS 10β Developer Beta. Note that an Apple ID linked to a developer account is required.