The "precedent" is more like the usual "we imported this and no one really cared that it wasn't technically correct so we kept going", isn't it? A single is literally not "part of" an album.
The notion of "single from an album" is fairly complicated, I think, and it doesn't seem very consistent to me, even for the more popular albums. For example, w:en:Dua Lipa (album) lists eight of the eleven singles containing tracks from the album as "singles". (The three that aren't listed are only included on the "complete" version, which was released about a year after the original album.) However, the oldest of those singles was released almost two years before the album itself was. On the other hand, w:en:Red Pill Blues lists only the latter three of the five singles containing tracks from the album; the second single was released nine months before the album was, and the third single was released two months before.
The rules for such a distinction might also vary from region to region; and if there were a complete set of data for an artist, it could be possible to query for singles associated with an album depending on how intricate the given rules are.
If there are actual definitions I think sticking more abstract concepts (e.g. "release for the purpose of album promotion" with an of (P642) qualifier – using of (P642) on the main instance of (P31) statement is probably too vague) into instance of (P31) could work, although this is really not anywhere near the top of Wikidata's music-related priorities.