In a word...NO
WAAS implies DO260B. As long as the right modeS 1090es transponder is fitted...and the paperwork is filled, submitted and approved....however, GBAS is a Ground Based Augmentation System...proprietary...licence...equipment...money
Just to add, Francis...do you remember that deal between AirServices and Honeywell a few years ago...system allowing CATIII approaches into a fogbound SY? That's GBAS.