Big problem with this theory, why didn't the few passenger phones that were almost certainly on, not get a signal over Malaysia or anywhere else.
Who has said they did not get a signal? Has anyone said that?
Some phones very likely did register with the network if they passed in range.
Passengers may have tried to use their phones if they realised there was a problem. But they may have tried to call, and voice contact would likely be fleeting. SMS is more reliable with marginal network, but I think your first instinct would be to call.
Plus passengers can use (non assisted) GPS even if no network coverage - although there likely would be no external evidence of this.