They do still offer this. You need to go to guest services at the park. You can go to the one outside the gates, or inside. The person who the pass is for needs to be present. If they agree a pass is needed, a paper one is issued. You need to present it to a team member at the entrance to the ride. They will give you a return time, and when you return, you are typically let into the express line. You can only hold one return time at a time.
Someone else can maybe chime in with more information. I believe If the disability is related to being in a wheelchair, they typically do not issue a pass as the lines are setup to accommodate them. The pass is meant to essentially hold a place in line for those not able to be in the line for an extended period. My daughter is on the spectrum and has a lot of difficulty being in close proximity to others. The pass helps immensely. We get our time to return, and get a snack or do a bit of shopping until our time.
Hope that helps!