If I remember watching the National Geographic piece on this they maintain that there were two storm cells. The first the aircraft was approaching prevented the radar from “seeing” the second larger cell that lay ahead.
And also that supercooled water froze on contact with the pitots and shut them down all at once.
The NatGeo program, IIRC, was made some time before the black boxes were found.
The boxes should confirm or disprove the theory that the pitots were all out.