I'd imagine they would do a new AIP ENR 1.5 but the equipment carriage requirements do have to start off in ANO schedules 4 and 5.
Whether they can do a new AIP on equipment carriage without amending the ANO first I have no idea.
I would speculate they do have to amend the ANO - if the equipment carriage regs were delegated to the CAA, why would the ANO specify this stuff at all?