My guess is that Stevie was never completely sure about Hronek. That's why he gave him a rather short term on the current contract, and that's why he is moving him now. And if it wasn't in his plans to give him another extension (where Hronek would've probably demanded more money, too), of course he moves him this year (for such a great return!) rather than having to move him at next year's deadline.
On the current roster situation, just call up Ed and move Chia to RHD. The guy isn't good anyway, so what does it matter on which side he is?