The reason the TFE731 and ALF502.507 engines had a centrifugal compressors was to route the final stage of compressed air to the inlet of the combustor. The combustor wrapped around the outside at least part of the turbine section with the exit of the combustor making a u-turn feeding the hot gas into the HP stage 1 turbine nozzle. I think this was done to cut down on the length of the engine, probably saved a foot or more in overall length plus a weight savings.
On the Pratt "PurePower" turbofan engine, I wonder how the PW1100G will handle the shock of a fan blade out or bird ingestion, especially the gear system?