I think a lot of the publishers you mention are excited about doing their own thing, though it's possible that they might support 5e in addition to what they are doing.
How important has DDI really been?
And for whatever reason, its a huge success. Bigger than imagined. It unites players from across the generations, streamlines and simplifies gameplay, cures devil chills, whatever.
Allow me some wild, rampant speculation.
Flash forward to 2013 and D&Dnext is out. And for whatever reason, its a huge success. Bigger than imagined. It unites players from across the generations, streamlines and simplifies gameplay, cures devil chills, whatever. People love the game.
The game also has a fairly robust OGL/third party contract, at least better than the GSL was.
I wonder, would any of the classic 3pp come back to support D&D? Would Paizo (having their own successful 3e clone), or Goodman (who just made their own retro), or Necro/Frog God or Kenzer or Mongoose or Green Ronin?
Even if Next sold gangbusters, would it be enough to entice any of these companies to rejoin with WotC, or is the 3pp fanbase too hopelessly fractured across too many side-games (Pathfinder, DCC, etc) to ever see these companies support a new D&D again? Has the 4e/GSL debacle soured them to ever trust WotC?
...We like the way paizo handles things...We are D&D players, we're just playing something with a different name right now.