I would verify the last backup of /etc folder to check the local.meta file that could be used to restore the previous condition. Other option would be the previous splunk diag files created, because the file will collect all the configuration that you had in the splunk environment and you can open it and extract the file you need to.
From I couple of times that I have to deal with meta.conf, I manually edit it to process any particular update.
Or possible you get a default.meta file from default folder and rename it to local.meta and copy to the app you need to. The problem here is that you have to tweak all the permissions again for all the knowledges, more manual work.