In my experience, contribution agreements, those voluminous contracts the government enters into with an independent entity, whatever the organization may be—which I, myself, have signed—normally address those statutory and regulatory elements you referred to. That means the organization to which the work is being contracted out has an obligation to comply with the legislation.
Now, to be clear, I don't know more than anyone else about the content of any agreement that may have been negotiated with WE Charity. I have no knowledge of that. Nevertheless, generally speaking, that's how contribution agreements usually work.