You are right, work on packaging GNOME 49 is still ongoing & may take a while (it is a hard job and not many people are working on it). It is not considered a dead end yet, as far as I can tell:
https://lists.gnu.org/archive/html/guix-devel/2026-02/msg001...
> my understanding is I'd need to stay with KDE Plasma in the long-term
Has KDE committed not to hard-depend on systemd in the future? I would be glad to discover that.