Highly unlikely IMO. Is an APO 28mm lens even a practical proposition?Of course, there's also talk of a new 28 Cron.APO? $7k?
More likely is a revised lens barrel design and hood arrangement using the same optics as the present Summicron. Such a lens would no longer be prone to having the front of the lens coming loose and it would bring it into line with the other newer lenses that use an externally threaded hood. Leica have form in this regard – revising the mechanics of a lens but sticking to exactly the same optical design – when they introduced the second version of the 28-35-50 Tri-Elmar.