For the recorde - adding paths to the list shouldn't cause data to go away. Something else is going on here. Also, I know in the past that people recommended (including me :)) to delete the translog on recovery problem but this is only when you run into translog corruption on old ES version, where we didn't shut down correctly and corruption was expected. These days are long gone and newer version will refuse to open a primary if the translog is missing.
I presume there is no way to dig deeper now and the data is long gone. If not please ping me and we can research.