I wasn’t really thinking of “what tool would we use” but more “how does community-involved roadmapping work?”
Of course, that’s not necessarily what was being sought here … I imagine that even “a high level roadmap published somewhere” is the kind of thing Uber was speculating about.
I guess to a certain extent the synopsis of notes I gave above is the OGS roadmap 
GaJ view of OGS Roadmap:
- Solve short-medium term moderation scaling
- underway
- Improve AI cheat prevention
- underway, continuous effort needed
- Aesthetic improvement
- Improve new-user experience
- Improve “overall” experience
- underway (“Play” page updated, new user joining flow experience updated)
- Improve Internationalisation and more broadly “International appeal”
- Trying to work out what effort makes sense
- Performance improvement
- Infra upgrades underway, ongoing/continuous
- Software (packaging etc) improvements later
- New features
- Largely on hold, behind the rest
- Incremental additions opportunistically
Disclaimer: I do not speak for anoek or OGS, I’m just sharing what my impression is.