At the time the script was written DEVONthink didn’t add CriticMarkup to the „Summarize Highlight“ output.
I‘m not sure what’s the benefit of using CriticMarkup here as CriticMarkup only supports one highlighting color, but PDF annotation highlights of course support any color. So what we currently get is a „Summarize Highlight“ Markdown output that shows all highlights in yellow, not matter if the actually used highlight color was red, blue or pink.
@runner57 I‘ll see whether it’s easy to adopt the script to the new circumstances.
As a workaround you could open the resulting record in e.g. BBEdit and do a search and replace for the CriticMarkup syntax. (Should also be possible to replace in DEVONthink)