Most probably... They'll use anything they can to boost their market share numbers.
Is it really as nefarious as you make it seem? Is Google allowed to count the number of browser that have Google search built in? Are they allowed to count Android phones where Google search is the default? Why would Bing not be able to count searches done on there just because they're done via Siri?
I'm not saying it's nefarious, I'm just saying they're desperate to show as large a market share as they can claim to. I used to work at Microsoft on MSN and helping Bing boost its numbers by all means necessary was job #1 by the time I left. Some of the means were not quite kosher.