I haven't heard anything from Disney, but checking the
Shop Disney site I found that it looks to be active now:
https://www.shopdisney.com/commemorative-legacy-paver-6-personalized-1516620
notes from the item page:
Please note: The 6'' Commemorative Legacy Paver is eligible for the Disney's Walk Around the World retirement program. Following the removal of the original bricks from Disney's Walk Around the World at Magic Kingdom Park, Guests who had previously purchased one of the personalized bricks are now entitled to a discount when purchasing a 6'' Commemorative Legacy Paver. Guests who believe they qualify for this program should email Walt Disney World Guest Services at guest.services@disneyworld.com or call 407-828-2701 with the name and hometown of the Guest who sponsored the brick (Please note: shopDisney Guest Services team are not responsible for this program).
I haven't played around with the purchase yet, but it looks like the images give a good idea of how to personalize the message lines, and I'm assuming you'll input your code at the time of purchase