I disagree with the statement of the OP , If ever we all HODL our bitcoin so it means the supply in the market will go low but since the demand is high they will start to increase the value of bitcoin and that is the time bitcoin will pump and that is the right time to sell.
It could create a majot problem and imbalance in the market. You can't succeed in bitcoin by just holding it because you will just turned out to be a collector. You must sell it so that your bitcoin will have its function. Selling it makes you earn a profit so you should go for it. Don't just hold learn to sell.