I don’t want to create confusion about this issue. 
Yes, if the user disables/uninstalls the JSON plugin, this will indeed be a problem for versions after 243.+.
In this scenario, perhaps the correct approach would be to move the JSON language-related features to the json.xml file, keep it as mandatory, and coexist with the other features that do not depend on the JSON plugin.
However, in practice, this is the strategy I have been using as a workaround since versions 243.+ to solve the verifyPlugin issue, and it has worked for me. I have no reports of ClassLoader related issues, and I have supported versions SinceBuild=231 to UntilBuild=251.+.
I currently use the plugins that fit this scenario and have no bugs related to ClassLoader.
Please note that the JSON plugin must be installed and enabled for versions 243 and higher.
//TODO I am working on moving the JSON resources and generating a SinceBuild=243 version.