scook
Any plug-in can work in the ProChannel but that is not the issue. The existing FX bin is important for backward compatibility. Cakewalk made a design decision to add the ProChannel in the X series. It would be strange for them to drop the ProChannel at this time.
The idea is not to drop PC concept!
The idea is to make PC act as a "new version/concept" of FX bin instead of "new feature" apart from FX bin, as it is now.
Just imagine you see your old FX bin in PC view, with some plugs already "magically converted" to PC Modules (those which have already implemented PC Interface). And once you get more PC aware modules (or replace PC unaware modules with PC aware in the PC/FX bin) your PC strip gives you all that advantages advertised since PC introduction.
At the moment everyone is forced to make a decision: should I stay "old style" without PC or should I use PC and accept the fact all my old projects should be reworked to use it, most of my modules will either stay in "obsolete" FX bin or go into PC FX containers (with extra clicks to open GUI). If merging is somehow implemented, there will be no such question, no extra conversion work. And who knows, may be PC will become a part of VST5 API...