I am confused by this ruling as well. At first glance it would seem as if this type of wallbot is legal again, except for a this Q&A (and Karthik’s response earlier in the thread).
I can only surmise that the definition of trapping has been changed without telling anyone, or that wallbots are illegal despite violating no rules, and the manual update just confuses things further by explicitly laying out all the rules that they do not violate (pinning, trapping, grabbing). I’m also hazy on what the difference between a “cage” and a “wall” is if the intent is to protect objects. What makes a cage legal while a wall is not?