They have always had a free site, a few years ago when we started getting the "this image has not been downloaded in...." they automatically would send it to the free site until "we" fought back. They changed it to a tick-box to donate and an option to pay re-keyword your photo or remove it.
First I've heard of
https://www.megapixl.com/ though.
I think Dreamstime has the option to donate it to the free site if it's not approved also don't they?