If you're contributing to Jellyfin and your existing feature PRs have not yet been merged, please don't fret. 10.9.0 was an abnormally long release cycle and something we do not wish to repeat, so your changes will get in soon for 10.10.0, which we expect to happen in about 6 months at most.
So it's okay, it will not take a long time even if it didn't make it to 10.9.0.