Nothing having to do with the technical aspects of the protocol significantly lowers the supply per day other than a block halving. To state this another way, we get the same number of bitcoins per day no matter what the difficulty or hash rate is, accounting for slight variances here and there. The only thing that can lower the available supply from the perspective of the miners is for them to hold their bitcoins instead of selling them down through these price walls on the exchanges.

Anyway, these sell-offs have been of larger volume than the number of new bitcoins being mined daily, so it's more likely that whales, miners, or any other individuals who have hoarded their bitcoins over a long period of time are now selling them off in large amounts, not the freshly mined coins being sold off, that is dropping the price.