During discussions about the possibility of adding XLibre support to NixOS, the maintainers deemed proposals for supplying alternative packages with an X server impractical. Reasons cited include potential ABI changes in XLibre, increased workload for NixOS maintainers, who would be forced to test two server variants, and difficulties in interacting with those responsible for XLibre, whose political views become evident much more often than necessary for technical discussions. Additionally, the low quality of changes emerging in the fork was mentioned.
NixOS users are offered the overlay mechanism as an alternative, allowing them to replace the original X.Org Server with any other package, including XLibre. In this case, the user is fully responsible for resolving any issues that may arise on their system. The status of XLibre support in other distributions can be checked on the 'Are We XLibre Yet' page, which is periodically updated by the fork's authors.
Source: opennet.ru
