This is great news! I'm hoping it's the leading edge for visibility into other parts of the project – CI, bugs, etc.
Had you considered using a GitHub repository, as Rust does? It might help with some of the drawbacks noted, particularly tracking changes and reviews.
The introduction of a public issue tracker will allow us to better
engage with our community, accept more contribution from outside the
seL4 development team, and better communicate the ways in which we are
changing and improving the seL4 ecosystem.