Many cfo actually have the biz dev unit under them. Google and my current company both have the biz dev unit under the CFO. I also worked for CFO at a mobile telecom and he was actually a key executive in charge of the 3g expansion. The role is actually much more than accounting.
Certainly Corp Dev is under the CFO. Seems that this is a CFO who wanted bigger things (like Noto at Twitter) and AirBnB didn’t want it to be there. Someone who was CFO at Blackstone had to have big ambitions.