Dclife believes the new Olympus 150-400mm PR lens will be announced around November 20 at the “Olympus Wild Bird Photo” event. An evidence is also the fact that Olympus has a livestream event scheduled for November 20 4am Tokyo time (November 19 US time):
Photographer Brooke Bartleson will talk at this event and she is known to be often part of Olympus product launch videos.