The answer is no. The front seat has just gotten safer.
The reason that backseats are no longer the safest places to sit has a lot to do with improvements in safety. Over the last decade, car manufacturers have installed both active and passive safety technologies. These include better airbags and forward collision warning systems.
The backseat, however, has not received those protections. As such, the front seat has gotten safer while the backseat has remained the same.
Federal law mandates frontal airbags to protect front-seat occupants. Manufacturers added other airbag systems to help improve protection in a variety of crashes. These systems protect passengers in side-impact accidents and rollover crashes. These systems focus on protecting front-seat occupants, but not backseat passengers.