They were previously supported to the same extent, so I wouldn't just comment them out without an immediate replacement. I suppose creating separate extensions for each of them would be an excellent starting point for people to flesh out support for these languages (i.e. by adding the comment styles), however we should wait with this until we have a better extension management system.
I would like for users to be able to open a language for the first time and with the click of a button download and install an extension that adds support for this language (rather than shipping all these individual extensions by default).