I know optus isn't responsible for fetch channel offerings but they do take a payment for providing the service. Many of us took up the offer based on the channels on offer. Without those channels the service ceases to be appealing for me particulatly loosing 2 out of the 3 channels that I watch. Perhaps offering a Netflix subscription or at the least a subsidised subscription would be fair compensation.
I'm not sure that's really fair though. For $70 you get the base Optus NBN. For $20 more you get a FetchTV Mighty (worth $400) and free national calls and one free FetchTV Pack (Value $6)
Essentially what Fetch content you want to add is optional and up to you. (I run my Fetch with no Fetch content for free). As a month to month subscription package you can decide what is on offer is not worth your money almost any time.
I'd also put it under swigs and roundabouts. Fetch have added channels in the past and not increased prices so its possibly fair they don't have to decrease them either.
But its early days with subscription packages in general. People are really not aware that all the content they record or "buy" or even just subscribe to is now no longer their own to control. What is available can be removed remotely due to a number of reasons at any time. Perhaps this will evolve into consumer protections that offer some sort of compensation.