I don't prefer anything. I'm all for the H5 beta. It was my main motivator to getting MCC.
That doesn't diminish the fact that Halo:MCC is still broken (to paying customers), and now they'll focus on moving forward with Halo 5. Ideally...why not fix what's broken first, before moving on to something new? Just sayin'.
Anyway, carry on.
They've been focusing on Halo 5 since well before MCC released.
There were 4 other teams working on MCC outside of 343. 343 likely had a small internal team dedicated to the game, who will still be dedicated to that game.