I imagine you are referring to ysth's remark "I'm working on a 5.6.3 just as soon as I learn enough git." in this p5p thread?

I don't know what Yitzchak plans to do (it's not documented anywhere) but I'd be surprised if it goes much beyond getting 5.6.2 to the state where it can be compiled with current compilers.

One person does not a supported release make.

Other than that, I think we are in furious agreement :)