They make it clear in their post: > Firefox has continued supporting HTTP/2 push as this wasn't too large of an effort until recently. > However in the past fe

They make it clear in their post: > Firefox has continued supporting HTTP/2 push as this wasn't too large of an effort until recently. > However in the past few months we've encountered some webcompat bugs only affecting Firefox through HTTP/2 push They are clearly saying that recently there has been bug report, and this blog post is to do exactly what you mentioned as other browsers do: reject H2 push and gracefully ignore it. There does not appear to be any hiding here.