As can be seen on https://www.npmjs.com/package/@mapbox/polyline/v/1.2.1?activeTab=code the released version is still missing the license field in the package.json. This does not make any sense to me as the package.json contains the meow version update, which is later in the commit history here... Anyways, could you maybe release a 1.2.2 which includes the license filed in the packaged artifact?