No, we can talk here about the basic idea. However, Zulip is geared specifically toward online group collaboration including the ability to upload documents, tag subjects for easy filtering and also for rapid chat. We can use this WP thread to announce meeting dates and times, for example, where we can have actual brainstorming sessions, etc.
Also, those that don't wan't to join the Zulip group could share ideas in this thread and the Zulip group could discuss in-depth.