Potential problems:
*probability of a large number of vandalism uploads (e.g. profanities instead of article title)
*checking and maintenance burden on Commons
*if the recordings will automatically be linked to Wikidata, burden on Wikidata community to verify uploads
*review of uploads would likely be done by a small subset of experienced anti-vandal editors, and in any case they will have to know IPA or speak the relevant language (which will likely be a language foreign to the wiki from which the recording came)
Necessary countermeasures:
*uploads must be added to a maintenance category or have a revision tag
*recordings must not be automatically entered in Wikidata or linked to from articles; a mechanism to queue for review before use would have to be devised
The consequence of this is that unless communities at large care about spoken titles, the maintenance burden will be resented à la Gather.
The mockup of the moderation mechanism is very un-wiki and appears to involve the app only. It would be essential before proceeding to propose and gain support for a desktop-based review mechanism which involves ordinary wiki processes, for example, making it clear how to unlink the Wikidata item and/or propose deletion of the file on Commons. As with Gather, building a new type of feature with a different moderation UI, not having the accustomed features or means of use, is likely to lead to rejection by core users who do the reviewing.