Bloomberg was merely regurgitating what HP told them.
There is no special Beats Audio chip. The audio chip used in HP's Beats Audio laptops is nothing more than an industry standard IDT HD-audio chip. You can verify this by going to the HP site and attempting to download audio drivers for any of the Beats laptops. This is of course not the same audio chip used in the Pre 3.
Making sure an audio output is sufficiently shielded from sources of interference is neither new nor unique to devices with Beats branding. It is SOP for any manufacturer that cares about making a decent product.
So, if we were to compare a Beats product with a similar non-Beats product using the same audio chipset, as long as both have been built properly--that is to say, sufficiently shielded from interference--distinguishing hardware with Beats Audio branding from non-Beats branded hardware would be impossible with the Beats DSP turned off.
Finally, ask yourself which came first: The FCC approval of the Pre 3, which would have indicated the finalized version of the hardware, or the Beats branding? This recent refresh of the Pre 3's spec page is the first mention we've seen of Beats Audio, but the Pre 3 first passed the FCC process on April 26th. Once a device passes the FCC process, the hardware cannot be changed without re-submitting it to the FCC. Even if the change does not deal directly with the radios, any change to the internal hardware structure can affect how radiation is emitted from the device and therefore must be re-tested. So, either the super-special Beats Audio hardware design was there from the beginning, or there is nothing particularly special about the hardware, and HP decided to slap Beats branding on it primarily for marketing reasons, possibly justified by the inclusion of a media player with Beats DSP. No points for guessing which scenario I find to be more likely.