watchOS 27 Siri app lets you continue existing chats, though it's a bit hidden

watchOS 27 adds a standalone Siri app with chat history, as on iPhone, iPad and Mac. On Apple Watch, however, you cannot continue a conversation from the app itself — you must invoke Siri by holding the Digital Crown or by voice, and the reply is added to the open chat.

• watchOS 27 added a Siri app that keeps chat history
• Apple Watch has no explicit button to continue a chat in the app
• You can continue a chat by invoking Siri with the thread open
• Siri AI requires specific hardware and may have a waitlist