Originally posted by GunsForBucks:

I think what they are asking is will there be a public test dev hosted "Server" to play with others to test cross play.

Not just a build they run.
At least that is my understanding from what they are asking.

I'm actually not sure about that. I think they sometimes ask participating players to join specific test servers. But as far as I'm aware, there are no fulltime testing servers hosted by IG. Players can help by using the PTB builds and report bugs, either here in the PTB sub-forum or on the respective Discord channel.