I don’t think so, see Unformatted Code Detector - #4 by jeanas - Discourse Feedback - Discussions on Python.org for which I didn’t get any warning.
One thing that mandatory onboarding would help with is screenshots with code in them, although OCR could presumably be used to print a warning on such posts like the existing “Unformatted code detector” plugin.
I don’t follow Bokeh, so I can’t judge if the plugin is working well or not.