I just oppose naming it "brand new". Its largely still just as broken as it always was. Fixing one issue per release will maybe get PHP to state comparable with other languages somewhere in the next century (if they stand still in the meantime).

Also PHP could easily add sane new stdlib if it wanted to, and keep supporting the old one as long as people want to. I just don't think anyone is really interested in doing so. Most PHP users don't care much, and few large companies that fund the work are mainly focused on keeping the ship from sinking.