Currently, https://www.jmlr.org/tmlr/editorial-policies.html mentions "The manuscript is submitted to OpenReview in anonymized form" and https://www.jmlr.org/tmlr/author-guide.html mentions "submissions must be anonymized", while both of them do not explicitly mention what "anonymized" means.

I assume here "anonymized" means something like "removing identifying information from what you submit on OpenReview"? It would be beneficial to clarify this somewhere. It would also be beneficial to mention something like "You should not try to subvert the double blind review policy by actively revealing your identities to advisory board members and (possible) editors and reviewers of your paper".