It assumes they will be for sale eventually, which is true. At that time supply will increase and price will therefore decrease unless ongoing growth is experienced.
He said "to keep the current price stable". Stable implies not changing over time starting from present day right? Or did you mean starting "eventually" that much money will need to enter the market to keep the price "eventually" stable? If so, I don't know what the relevance is of how many coins are being mined this year or next. If you're just talking about eventualities with no timeframe, then you're not saying anything quantifiable at all.
