Might be missing something, but I'm fairly certain that Mapbox requires you to include attribution here. They also prohibit printing for commercial purposes, although that's lifted for enterprise plans, which you might have.
This is using Mapbox vector tiles with a style custom designed by the ellotand, right? Does Mapbox really prohibit using a product created that way on their platform and can they?
I don't know what the law is, but in principle at least, the selection of the data to include in the tiles (in general and for specific scales) and processing like generalization are both "cartography" at least as much as they are "database queries".
Was quite certain of this too. To cover something like this website is quite expensive too, and as this is a side project I highly doubt he's covered those costs.
