Probably true. Microphones, receivers, buttons are very mature stuff and all alike. Any “magic” is in the processing chip.
I’m sure it is better for somebody. Is it twice as better for YOU? Your provider thinks it might be, but only you can decide.
Finding that last bit of “better” represents years of research, thinking, listening, study, and code-wacking. Keeping the programming competitive with other brands is far more expensive than the hardware. Too expensive for many users to swallow. OTOH there are people who make more money if they hear better and it makes sense for them to spend a lot more. So the must-have buyers pay the development for the cheap guys like me.
And yes, “re-flashing” is so obvious that the HA makers must have protections. Such protection has been around since the dawn of computers. In the current state of the art, the processor probably has all programs onboard, and a secure byte which tells it what program to use. A “Demo aid” may allow changing the setting; my Phonak seems to need a code from the factory, and will expire if not paid-off in 30 or 90 days. To avoid even this temptation I’m sure my non-demo “30” has that model-byte ZAPPED into the chip and there’s no microscope small enough to change that.