Disclosure of the "halt catch fire" bug

[neldredge]

The whitepaper mentions that a "halt catch fire" bug was found in an unnamed CPU, and that more details would be disclosed at a later date. Now that it's four years later, did that disclosure ever take place?

If so, perhaps the paper could be updated with details or a reference?

If not, is there any explanation of why not?

[ZhaoZhen711]

I believe it was said in the DEF CON 26 talk GOD MODE UNLOCKED Hardware Backdoors in redacted x86.
Chip was the Via C3 or C7.