They're probably referring to https://developer.apple.com/documentation/mapkitjs which is what powers the DDG integration.
Anyway it is the case that the only way to browse Apple Maps via the web (AFAICT) is via an integration like DDG: https://www.makeuseof.com/tag/how-to-use-apple-maps-right-in...
So yeah saying it is available on the web feels a bit disingenuous, but it is, kind of, indirectly.
> Apple Maps is available on the web