No idea. But I've integrated their API to a commercial project (https://bookmarker.cc) without any issues. Users are exploring The Met Collection and save images to their library directly in the app.

> Through The Met Collection API, users can connect to a live feed of all Creative Commons Zero (CC0) data and 406,000 images from the The Met collection, all available for use without copyright or restriction. The Met Collection API is another foundational step in our Open Access program, helping make the Museum's collection one of the most accessible, discoverable, and useful on the internet. The Met Collection API is where all makers, creators, researchers, and dreamers can now connect to the most up-to-date data and images of artworks in The Met collection, representing five thousand years of human history.

source: https://www.metmuseum.org/perspectives/met-collection-api-2