This game went Early Access far too soon. It was too ambitious in some areas and did not focus enough on what is needed to drive and maintain online player count. Guessing at the revenue generated (copies x cost: ), there should have been ample funding for a few dozen simple maps. For example, UT4 is in a less polished state but has plenty of untextured "Work-In-Progress" maps, with just enough fully-completed ones.

So it's put me off buying Early Access in the future, but I'll still give Toxikk a go out of loyalty, if it ever gets a proper 1.0 release. Unless Lawbreakers gets released first, that is...

No idea if the source code will be "officially" released.
But you can compile your own code against the .u files that came with 0.94.
I don't have access to the "official" source either, but but that doesn't prevent me from using Cruzade.u classes in my own mutators.
We can discuss the details in the Discord modding channel if you like.

I already compiled unrealscript with Toxikk, Chatouille even provided useful content for doing so more comfortably. Though, that is no official modding support. I'm sure *(that was) mutators were part of the 7 advertised facts about Toxikk (now 5 facts?). Official statment, please?