According to recently rumors on SAR, along with new Sony full frame mirrorless camera, a new FE lens Sony FE 100-400mm G lens is rumored to be announced in April, next month. It will be the first full frame telephoto zoom lens for Sony full frame mirrorless cameras. This new FE lens is currently in developing by Sony.
I heard from source that Sony is developing FE100-400G.
If development is in time, it will be announced with a new camera in April.
Price and specs of this FE 100-400mm G lens is currently unknown, stay tuned for more info.