No, if you don't have that extension installed and you get KML files, then my theory is kaput.
In my case, I always got csv files when I did an 'export as csv' from the mission hub. VLM would then process that file into KML and start Google Earth and the mission would be in your temporary places.
After installing the VLM Chrome extension the Mission hub started creating KML files when I did an 'export as csv'. When I turned off the VLM extension, the Mission hub export returned to the old (csv) behavior.
So based on that, I figured the VLM extension was responsible for the KML files. Now, I'm not sure what caused the problem, but I am happy to be able to use Chrome with Litchi again