It's an interesting question.
MC's own "remove tags" option gets rid of just about
everything, which is, I suppose, to be expected.
Currently, what you ask is not possible within MC. JRiver
do like, wherever they can, to fill in missing bits of workflow that neccessitate the use of a third party app, so, you never know, dev time and finance permitting, this might come to an MC build in the future.
In the meantime, whenever I find myself in this situation, which is rarely now, but in the past, when I was trialling one image app after another, which filled the file's tags with all manner of rubbish, I turn to the rather good, free for personal use,
XnView MP.
In there, under "Tools > Metadata > Clean", one of the options is to "remove all other app markers", which does exactly what you ask, in that it removes the MJMD tag block, preserving all other IPTC, EXIF and XMP data.
Once done with that, go back to MC and run the update tags from library on them all to have MC write the current MJMD tag bock back into the files.
-marko