It’s not really what Picard does. Picard can do that—natively by “lookup disc” to submit Disc IDs or via plugins like “Add Cluster As Release” (I guess it can also do ratings and collection management?)—but it’s not really its main function by any stretch. Its main function is to fetch data from MusicBrainz for the user to utilise for file tagging purposes.
In the same vein, the new Android MusicBrainz app will not have support for doing MusicBrainz edits. Maybe tags, ratings, and collection management—as those are the things that the API/WS allows to submit “edits” for.
To return to the topic:
I’ve been using Street Complete myself a fair bit, and have been thinking a lot about how to make something similar for MusicBrainz. One of the strengths of Street Complete is that you’re out there. You’re on the street you’re being asked whether it’s lit or not and whether its surface is asphalt or gravel or concrete slabs. This is one of the strengths of Street Complete as I see it: it connects to the environment you’re in in the moment.
How can this be translated to MusicBrainz? Should it ask questions about the music you’re currently playing? Should it ask questions about the music you have on your phone? Based on your listening history (if coupled with your ListenBrainz profile)?
And what questions should it ask? “Is this artist male, female, non‐binary or other?” “When was this artist born?” “Is this a person or a group (or something else)?” “When was this release released?” All of those questions shouldn’t really be answered without a source in the edit’s edit note, which you can’t really easily provide while on your phone. For Street Complete this is easy: the source is that you’re on the street and you know how asphalt looks different from concrete slabs and you can see that there are lit street lamps that are throwing light on the path/road.
What it could maybe do is ask questions such as “what genre is this?” “What mood does this convey to you?” – which could feed into folksonomy and genre tags in MusicBrainz and/or maybe be hooked up with feedback for AcousticBrainz; “Is this more happy or more sad?” “Does this have vocals or is it only instrumental (or only vocals/a cappella)?” “Is it acoustic?”