For transparency, I would like to share my accepted papers' anonymous peer reviews, if my coauthors unanimously agree. Some journals partner with websites such as openreview.net (which share reviews even for rejected papers), others may have that included in their process, but in most cases, nothing is said about sharing reviews by the authors (though it is sometimes explicitly said that reviews cannot be shared by the reviewers).
Are there any ethical issues with that?
I could perhaps see intellectual property issues (are reviews the property of the journal? of the reviewers?), though in our field, journals at least allow to have the author's version of the paper downloadable from the authors' website (so, why not the accompanying reviews?). More importantly, nothing is explicitly said about that on the websites of editors and journals.