The W model has Bluetooth, the plain version RP Pico 2040 version does not. BT has always been possible to use but under a non commercial license.
It shipped with the hardware, albeit unused. They always intended to go back and add Bluetooth support, so it’s nice it’s here now.
Isn't BlueTooth the same spectrum as WiFi so if your chip can do WiFi it should be able to do BlueTooth?
Different Media Access Control and framing. They're only borderline related, even in terms of radio channel definitions (they overlap in the 2.4GHz frequency range, but are incompatible).
Your microwave oven is around the same spectrum(2.45GHz). Doesn't mean that it will be able to transmit WiFi or Bluetooth, but it might interfere with both.
Technically, if it is just "a fancy SDR" and not some hardware dedicated just for WiFi