Whatever they trial at one park often ends up in the others. These types of passes are the natural progression of the industry as the parks get more and more crowded and they have more top-tier attractions added.
I remember the days when we bragged about SDC always having short lines and super efficient ops, not to mention cheap(ish) amazing food that you didn't have to wait all day for. Time and crowds have simply caught up with them as the secret leaked out. Well that and they added a ton of giant coasters, lol.