Some projects of Signal-compatible clients and forks received a message from a Signal representrive requesting they stop distributing unofficial clients that connect to their servers.
That probably has on shilling effect on Linux distribution that may be considering building and distributing Signal in their repository.
They can't possibly provide a package for every distro.
Signal's model, ie keep tight control over development and distribution of the client, and the absence of federation, it well suited for Apple/Google's stores, but not at all for open-source and Linux' ecosystem.