Will this be updated for Shadowlands?
Do you guys use any utility/script to automatically convert the name of debuff/abilities to OGG files?

Yes, it will be updated for Shadowlands.

The generation of OGG files is mostly automated, but I still have to go through the BigWigs modules to pick which spells that should get a voice callout and what it should say.

tools/generate.txt: reads the spells-*.txt and generate WAV files using text-to-speech
tools/encode.txt: encodes all WAV files to OGG

Yes, it usually gets updated after modules are finalized. The scripts are included in the repo.

thank you for your responses