There is no reason to assume the opinion of suppliers should have a major impact on price at constant supply.
Sure, Bitcoin does indeed have a lot of small miners who might tend to sell at certain times rather than at others. But that is exactly where speculators come in, acting as a buffer against such fluctuations. Bitcoin has a massive amounts of speculators, their opinion should dwarf what miners decide about doing with a month's output.
A miner who decides to hold no matter what is nothing more than a speculator in the end. Whether he bought the coins at some price or the hardware for another makes little difference. Just like a speculator, some got the coins cheaper early. There is no time-frame in which an ending amortization time should cause more coins to be sold than at another time -- except immediately after a price rise, which obviously didn't happen much, given the speculative bubble we've seen in June. Had lots of people sold off mined coins when rising prices made their value met expenses for their hardware, the extreme price spike would probably not have happened.
Also, I find models focusing on mining increasingly useless, as the fraction of coins that have been recently mined grows smaller by the day. With over 7.2M BTC created, daily production is now falling below 0.1% of the existing coins. The relative fraction keeps diminishing, and they are shared among many small miners these days.
That said, I believe the statement to be false. Miner hardware amortization time may be important for difficulty, but is unimportant to price. Speculation is dominant, and thus the important part lies in the expectations of those holding or buying BTC.
PS: I find it bad practice to chain words like "real, actual, true, accurate" in a topic. Interestingly, such findings correlate well with false statements inside.
long term speculators should have very little to do with the value of any currency, including bitcoins. The value of the currency will be driven by the demand for goods in the bitcoin economy by those outside the bitcoin community (exports) verses the demand for goods outside the bitcoin economy by those inside it (imports). I see imports to be drastically higher than exports; therefore, prices will fall until imports and exports equalize.