The blockchain was not publicly observable or observed for those 2 years. We have no reason to believe it is true, and even if it was true it still means that ~151 billion of the 184 billion BCN (82%) were mined prior to its public release. Think about that pragmatically. Would you want to use a currency where unknown actors controlled over 80% of it? This alone takes Bytecoin from being decentralised to being centralised by virtue of those controlling the flow of the currency.