Mansfield, Boeing still uses 200' for an AH for cetification issue with the caveat that operators can apply for lower AH's and the 50' figure is pretty much standard. Some carriers use Zero and as long as LAND3 is visible on the PFD/ASA/AFDS they continue to the autoland. I'm not aware of any FAA restriction or policy change regarding the 50' AH at this time.
Thanks for your reponse!