I have no idea. I haven't used bugzilla in many, many years.

I'd be happy for neither though. Markdown's origins were such that you could write plaintext files that could not only be easily converted to html or some rich format, but were easy to read as-is.

Displaying the plain-text of an issue in fixed-width font would be fine.

Markdown is supported in the Mozilla fork, which is what upstream is being harmonised with.