>But a seven-eighths "super, super, super-duper majority," she said, "is new as far as I’m aware."[1]
It is relatively standard for propositions to include some ways for the legislature to amend the law. It isn't a full legal requirement, but it is common. The a 7/8 majority is nearly impossible to reach on anything but the most milquetoast bills. That requirement was seemingly included so they supporters of the bill could feign that it was flexible while not really conceding any possibility of it being changed. If Prop 22 is going to be amended or repealed, it basically has to be done through the popular vote.
[1] - https://calmatters.org/politics/post-it/2020/10/california-a...