I've been in touch with Jolla about feedback and channels.
They have no plans right now to establish a forum and are happy with keeping things organic and letting the broader "community" look after things.
Certainly, restructuring TMO to provide dedicated software and hardware sub-forums will better enable anyone who might be checking in to see what is happening.
Posts on Twitter are directing community to this thread to discuss and put forward ideas. Jolla are aware of this.