These are restrictions on authors submitting to journals, not restrictions on repos themselves. You can have a preprint repo hosting whatever you want. It doesn

These are restrictions on authors submitting to journals, not restrictions on repos themselves. You can have a preprint repo hosting whatever you want. It doesn't mean that a researcher with a paper published in a given journal can upload it. If people can't upload their papers while still abiding by the policies of the journal, then your repo is kind of useless. Both publishers and individual journals often have restrictions on preprints. This is a very common one with major publishers. Just because you aren't aware of these restrictions doesn't mean that they don't exist. I have worked with preprint repos in the past, and this is very common.