Not going to happen.
Bethesda have creation kit, is a tool to make game parts, CDPR have some extraction tools, the community makes the hard work. Bethesda had to make huge changes to get PS4 mods, and even so is limited, because sony have proprietary formats in almost everything, textures, sound etc... So the modders would need to have access to these tools, and sony will not let this happen.
For what i see as a modder myself, bethesda is easy to mod, other games like xcom and city skylines are too, they have dedicated tools for that, they want the community help their games, so you don´t have to spend much time "breaking the system" to make what you want to make.
So, back to start, not going to happen, CDPR will not release friendly tool to mod their games, they can help the community giving some info or the endorse, but i really don´t think they will release a modding tool like W2 have.
Just one observation, for what i see in the modding community, is very difficult to find a modder that makes good scripting/coding and artistic, for what i see, or is good in coding or in sculpting/texturing etc... Without a proper modding tool, you let just the good coding guys modding.
Another more thing i forgot to say... Skyrim, FO4, Cities Skyline, XCom etc... any game that have proper modding tool, let you add stuff to the game, CDPR games let just change stuff in the game.