GLS actually is CAT IIIb capable, but not approved so far. So blind landing with that is completely possible, and the best bit is, you do not need an onboard database for that as the approach geometry is broadcasted by the groundstation.
As noted, the signal does certainly qualify for CAT III autoland procedures.
While not approved for commercial, there are many military entities, including helo, that use GBAS CAT III autoland.