Gadget
Inspect and edit as needed.

• MediaWiki:Gadget-LinguaImporter
• **MediaWiki:Gadget-LinguaImporter.js**
• MediaWiki_talk:Gadget-LinguaImporter.js

Inspected the page. This is indeed the intended behavior: languages which produce audios files get this tag and value. Sign languages get another value.

The LanguageImporter.js code is here.

Older languages may miss this data tho. 1) Need to check. 2) Create a task to update old Qid language items where Commons category and p_24 (MediaType) are not defined.

If I understand correctly, it should no more be removed the P⁠24 := audio, but it should be added on every language item (except sign languages where it should be P⁠24 := video).

According to the following request to be executed here, there are currently 561 languages, whose 53 have P⁠24 := audio and 1 have P⁠24 := video.

SELECT ?language ?languageLabel ?code ?type
WHERE {
  ?language prop:P2 entity:Q4 .
  OPTIONAL { ?language prop:P13 ?code } .
  OPTIONAL { ?language rdfs:label ?languageLabel . FILTER( lang(?languageLabel) = "en" ) } .
  OPTIONAL { ?language prop:P24 ?type } .
  #?language prop:P24 ?type .
}

I searched "sign" and there is only Q99628, so I guess all others are audio languages.

Also, I see some specific "languages": Q367 "Judeo-Arabic languages" (macrolanguage), Q364 "Middle English" (historic), Q368 "Egyptian" (extinct), they can be tagged P⁠24 := audio, but it can be debated (collective language or reconstructed pronunciation, it could be used subclasses of Q4 or qualifiers).

If the purpose is to indicate whether selecting this language triggers audio recording or video recording, I think that the P24 property should indeed be added on every language item.
But a more important question is about how we manage languages importation from wikidata, and why we import them individually, please see T284645