The Spotify model is similar.
The key difference is that while users pay into the pool, they don’t determine determine how the pool, or their portion of the pool, is distributed. Plays determine distribution, but not a single users plays, all plays.
If all github users donations entered a single pool, and that pool was distributed to projects based on the number of clones each repo received, that would be similar to the spotify model.
But I don’t believe that’s being proposed.
Rather, a user sets up a donation amount, which is then distributed to the projects they include in their “sponsor pool”.