Mark CMG
Creative Mountain Games
My first thought is that this has to do with SRD. Or, rather, the lack thereof.
I hope not, but that's my gut instinct.
Thaumaturge.
That's a likely takeaway from this news. However you look at it, it is big news.
My understanding is that the full time corporate environment within WotC is challenging.
That's one way to put it. Hang in there, corporate workers!

Monte's been his own boss for ages. It's hard to go back into an environment with a lot more bureaucracy.
I doubt this falls under the rigors of corporate life and suspect the difference of opinions is more fundamentally to do with management/legal expectations regarding how the design process and end goals are to manifest. It's not much of a surprise after reading infomation from threads like this -
http://www.enworld.org/forum/general-rpg-discussion/322062-re-building-halls-undermountain.html