Antonopoulos talks about that in this vídeo.
He says all coins have been in casinos or mixers, and exchanges will look just a few transactions back in history.
I agree with him and that is only logical thinking.
Only virgin coins are going to come directly from mining or ancient coins that are never moved (many of them are lost forever) will have no history.
Now imagine any government that seizes bitcoin from anything they consider illegal, they will blacklist those coins, but after few years they will sell them
What is going to happen with those coins now? Are they ''whitelisted'' again??
Such a silly concept.