If Bitcoin really reaches $8000 then people's confidence in crypto currency will decrease a lot. Many people have already lost faith in Bitcoin because of some coin scams.
Many people may panic if Bitcoin drops to $8000. But that doesn't mean all people will begin to leave Bitcoin. For those people who believe in Bitcoin future, it should be a time to buy Bitcoin at a very cheap price. More drops, real Bitcoin holders probably buy more. By the way, I assume only people with a weak trust in Bitcoin who are worried about Bitcoin and think it to drop to $8000. While for people who are confident with Bitcoin, I am sure they never think that Bitcoin price to drop below $10000, even if it is not impossible.
Undoubtedly, a fall in bitcoin's value to $8000 will create a huge panic in the cryptomarket and massive sales of this asset. This is on the one hand. On the other hand, as you say, bitcoiners will act in the opposite direction and will buy back btc at a cheap price. This will serve as some counterbalance and prevent further falling. At least not from a hard fall. But to be honest, I don't expect the price of bitcoin to drop to $8000 at all. It was already discussed in one of the threads that the suggested lower limit is ~$13.000 based on historical comparison with previous bitcoin drops.