Where is this information coming from? IMO it isn't reliable unless a source is listed. Part numbers are great, but this is the only place I have seen any information regarding a 'fix' for the 3000ES.
I've noticed that the 3000ES is not in stock at my local stores, and even Ebay merchants don't have the 3000. Onecall? Nope, no 3000.
The 2000 and 5000 are abundant everywhere, and the function with no hiss unless you turn the volume all the way up. I don't see why they would need to be 'fixed', unless Sony is going to make them even quieter (which would be great).