There's an old issue here, but I'm not sure Scott works for Pulumi anymore.
https://github.com/pulumi/examples/issues/1441
From my perspective, there's a top-level license that does let you use + modify, and then something in each file that technically revokes it.
This is likely just a mistake though, as it goes against some of Pulumi's public statements around being pro-open, and it'd be problematic to provide examples that people aren't even allowed to use ;)