Just because an area is closed to one type of use or another does not mean that it will always be that way. The adaptive management approach recommends that the MPAs be re-assessed regularly, and during that assessment the MPA designation can change.
The Marine Life Protection Act (MLPA) allows CDFW to re-examine MPAs and the MPA Network to determine how effectively they are meeting MLPA goals. This examination is accomplished during what is known as a Decadal Management Review. Every 10 years California's MPAs are assessed for effectiveness. Changes may be necessary, either to individual MPAs or the Network as a whole, depending on how well the MPAs are meeting their goals.
It is also important to recognize that the MLPA requires by law that California have an MPA network. Unless the law is repealed California has a legal requirement to have a MPA Network into the future.