I don't quite understand. Raven wanted to provide the source code but LucasArts didn't allow this. Now that LucasArts is no more Raven simply did it? It's weird, after all, it's not like if a company ceases to exist others can do with its stuff as they please.
Yeah, the exact circumstances are confusing BUT one thing that was mentioned is that the actual source releases say "copyright Activision 200X" which makes me wonder if it wasn't Activision that signed off on the actual release of the source.
EDIT: From the Jedi Outcast source page:
Activision and Raven are releasing this code for people to learn from and play with. This code is copyright Activision 2002. This source is released under GNU GPLv2.
Or, and this may be going out on a limb, Raven might own their own source code. Think about it. Anything in the source is technically copyright of the studio that made it. Other than references to Star Wars characters and tropes, nothing in there suggests that LA would have to sign off on it. If they'd released the assets, on the other hand...