Here is an email directly from HTC a few minutes ago.

"I understand how important it is to know the extent you can customize your device to and I appreciate your interest in software and development. HTC is not aware of any Root Kit or Blocking feature on the G2. It is quite possible such a feature was added by Google or the Carrier. Please be aware that third party roms even on our older devices do void the warranty on a phone and we can not support them. The only thing we would be able to do is direct you to some of the feedback sites and our support forums located at http://www.htc.com/ us/. We can only support the ROM that came on the device or updates provided at carriers request for a device."

Sent from my T-Mobile G2 using XDA App