Verified answer
Does a supported interface language guarantee matching voice audio?
Quick answer
No. Steam uses separate columns for interface, full audio, and subtitles, so a language can support menus and text without a complete voice track.
What this means
Language pages record those columns independently. Console versions can package languages differently, so the regional product listing remains the final purchase check.
Official source
Steam — official language matrix
Continue with the relevant guide
Open the related Control Resonant guide for the current topic summary, connected systems, and any later verified changes.
This answer is reviewed against pre-release official information. It states unknown boundaries explicitly and will be revised when Remedy or a first-party store publishes a newer fact.