Opinions among electricians seem to vary. I asked mine about it before installation - he looked into it and said it wasn't required.
I am a non practicing electrtician, and I really suprised that an electrician can come to the conclusion that an isolator is not required. I mean, I am not particularly worried if they don't choose to install one, but I wouldn't. I have just tried to satisfy my curiosity by spending 30 minutes reading the Wiring Rules (AS/NZS 3000:2018), and while I can't find anything specific for this particular case:
1. It's common practice to install an isolator (switch) on any directly connected electrical equipment, there is only on exception that I am aware of; and that is an oven or microwave (that being an enclosed cooking device), which come to think of it is a little odd in itself. Generally the idea is to be able to swtch off the device whist someone is working on the equipment for safety (may or may not be electrical related safety, eg moving parts etc)
2. All socket outlets (with the exception of one installed for the specifically for the purpose of a luminaire) are required to have a switch. I'd consider an EV charger to be close enough to a socket outlet. There is a whole appendix on EV chargers in current rules, it makes specfic mentions of "socket-outlets" being one form of connection, and "vehicle connectors" being aother. Basically, if you have provided a socket outlet for the purposes of pluging in a portable EVSE (or Fixed EVSE but you have attached a plug to the input), that is the socket-outlet method. If you connect via a Type 1 or Type 2 connector, that is a "vehicle connector" method.
3. I would feel better if it was possible to quickly switch off power both for convinience and for a possible safety issue should somthing untoward be happening.
4. If your electrical install is randomly audited, I would expect an inspector to defect the job, regardless of wether or not its techinically required. Just for the fact that he/she might not be sure either and would err on the side of caution. You could try to convince them otherwise, but if they didn't agree, you'd be going back to install an isolator, wasting time, paying for an isolator you didn't charge the customer for, looking like an idiot to the customer and potentially having to completely change the position of the charger etc.
5. As the customer, I'd ask for an isolator just to avoid potential hassels as listed in point 4.
6. The rules should just remove the question by specifying one way or another!!!
No idea if I am right or not, but thats my take.