I think it will succeed, it's using source 2 which is only used currently in a VR game and dota 2, the hammer editor is more extensive and creating addons is much better, it could explode much like gmod did.
I hope it is great, I have been waiting for this game for a long time since it was announced by Facepunch, I hope it fixes a lot of bugs than it has in the standard Garry's Mod.