UE3 License / Source Code in 2017?

It’s been quite a while since Unreal Engine 3 was released, and since then, it’s source was never released or shown to the public. I’ve heard that the actual reason why Epic Games didn’t want to do so is because a lot of third party developers made their changes to it’s code, making it hardly understandable to others or something? In any case, I’m writing this question since I’ve heard that it’s no longer possible to buy UE3 license anymore, and if I’m not mistaking, it’ll take away the possibility to buy the source code, too. Is it… a truth? I was always planning of buying it someday, and I thought that it can be done at any time, but I was already late? And… In this case, it’s impossible to get the source code? I just wanted to rewrite the iOS platform support, add different newer shaders, change the way configuration files looked like, since… I already have the experience of doing something like this, but… It’s not going to be possible to do at all? (upset face)

No promises, but you can make a request for a custom license here.