as far as I know there isn't an article documenting the hardware change, it's a fact that hroark and other dev type guys have found in working on the kernel source code, read up on hroark's kernel thread for proof. I don't think it's something ZTE is advertising or admitting.
It's just speculation, but having been around since day one on this forum for the zte warp, I know that the hardware/software was sketchy and buggy at best from the beginning so I can only assume that the hardware change was either a cost savings effort and or an attempt to correct some of the force close issues... I know the software was adjusted about the same time and have to assume it was put out to account for the hardware change and to try to minimize the force closes...
in my case 90% of my force closes have been fixed by the b08c update, so that rules out hardware in my case as the root cause of the majority of the reboots, the other 10% of the reboots that still remain (like once a week maybe) are probably related to my phone being one of the first ones on the old hardware and also I believe that the software still has something in it that causes the issue.
I think we might see even more stability after the kernel gets fixed/tweaked soon by hroark and shin, but some of you just got unlucky with bad hardware, send it back for a replacement is my best answer.
I have never experienced an issue related to CWM or root that wasn't caused by user error, those two things aren't going to be the reason for reboots.