Omarchy is an independent open-source Linux distribution, not an October project. October maintains a fork for integration work and sends generally useful improvements back upstream rather than presenting the distribution as its own.
The fork exists for integration work. Changes that help everyone are contributed to the upstream project instead of being kept private, so the wider community benefits from October's work on the distribution.
October's integration fork lives at the october-dev/omarchy repository, and the independent upstream project is basecamp/omarchy.