It's completely broken.
Server side the ordered_content_collection and user_collections page provider definition have
meaning we'll likely have a resultsCount negative which breaks the lazy scrolling.
Client-side, the nuxeo-collections.html element has not been adapted.
Moreover, Collections and Favorites unit tests were not passing anymore and were temporarily disabled (https://github.com/nuxeo/nuxeo-web-ui/commit/2aaa0a59ef3d21be0fb3534acd797c8477167471) and they need to be fixed/updated.