The package now provides two separate bundles for umd and ejs. dist/olms.js is the umd bundle, dist/index.js the ejs bundle. No other JavaScript files are provided in the dist/ folder any more.
Imports from the dist/ folder are no longer supported. They need to be replaced with imports from the package, e.g. import {stylefunction} from "ol-mapbox-style" instead of import stylefunction from "ol-mapbox-style/dist/stylefunction".
The apply() function has been replaced with an alias of the default export. This means that apply() now returns a Promise<Map> instead of a Map.
The auto-generated types are now stricter, because they reference OpenLayers types correctly, instead of using any.

apply(), applyStyle() and applyBackground() now take an options argument, which can contain a transformRequest option. With that function, urls and requests for styles, sprites, tiles and data can be modified. This can be useful e.g. to fix relative urls or to add credentials.
Another available option is accessToken. In combination with the new support for mapbox:// urls, it has become much easier to use maps and styles from Mapbox.
Finally, a set of resolutions can be configured in the options. This makes it much easier to work with layers or maps in projections other than Web Mercator.
The applyStyle() function has become more powerful and can now create and populate the source of the provided layer.
feature-state is now supported. The new functions setFeatureState() and getFeatureState() can be used to set and get the feature state.
The build size is now at least 80 kB smaller because of pre-processing of the style specification from the @mapbox/mapbox-gl-style-spec package. The umd bundle no longer contains the OpenLayers code that has been there by accident for a few releases, which had unnecessarily increased the build size by almost 400 kB.
The API docs are now generated with typedoc instead of documentation.js