We always talk about bitcoin’s scarcity and aswell the 21 million hard cap and the idea is to increase scarcity. Record has it that the estimate of bitcoin that has been lost so far is 3 to 4 million i.e we can never have the 21 million because the lost ones are not available in supply but counted as already mined. A Bitcoin is speculated lost by longterm inactivity of longterm holders.
The thing is that the lost Bitcoin has been mined and counted toward the total supply cap.
The information or number of lost BTC provided may not be accurate because most lost BTC is calculated using on-chain forensics to analyze inactivity and statistical models, with no direct measurement.
Which i believe researchers see as BTC addresses with no activity for 5-10+ years as lost.
if 1 million coins from already considered lost hits the blockchain, will it trigger a short-term panic that will result in market dips and uncertainties in the mind of holders?
No.
Now, How can we create the difference between a long term holder and a lost wallet?
There's no way to differentiate the longterm holder wallet, which is seen as dormant now and lost wallet unless the wallet owner comes to claim ownership through a signature message.
If the recovery result in a drastic dip, what is the tendency of bitcoin bouncing back to the original price.
The tendency is already created through the concept implemented by Satoshi to maintain BTC market inflation.