Let's say you got bitcoin (or any other coin) back when it was very cheap. You bought a hardware wallet, and you held it through all of these years. It's now worth hundreds of thousands (or more). Is it safe to say that you're still likely to be asked for the source of these funds even when they can see the funds has been moved from a dormant address?
It's possible since 1 BTC is worth $118k nowadays so if one one-time deposit is made. It's very likely that the exchange will ask you for that for compliance with the government ruling if you are going to trade and sell that off through a common exchange. But I think doing that in batches if you're going to sell them, might not put that transaction at risk. Maybe doing a couple of thousand per transaction won't trigger them to ask you for another compliance if you're done already with KYC. Because they usually follow up on another KYC.