The first major drop in diff came after the drop in price at the end of 2018. (see? price dropped first, then hash-rate followed, not vice-versa).
I by no means said or even think that the vice-versa of your theory is valid, I always say that to phill in his difficulty-related topic, but maybe I need to make it clear that what I think is.
- Pirce follows difficulty > wrong
- Difficulty follows price > debatble.
You see, you can have a dozen reasons for why that happened, but they all don't change the fact that "difficulty follows price" might be wrong, what matters is, bitcoin price has been going down for nearly 2.5 years, the difficulty has been going up for 10 years, which means in the grand scheme of things difficulty can only go up and there is really no effect of price as far as the long term is concerned.

If price remains sub 7k even after the halving, we will see a major drop in hash-rate.
I agree, but you see this is a whole different factor, the halving is a special factor, which is kind of off-topic, I am talking about when there is no halving where all that matters is the price and its relationship to difficulty, in fact even port halving and with prices remaining below 7k, the difficulty will INCREASE in a few months after the halving.
So, Prices below 7k after the halving, a good temporary drop in difficulty for a few months, prices remain below 7k won't stop difficulty from rising again to ATH before price even goes past 10k, why do I think that is possible?
gear efficiency, more gamblers entering the game, newbies have no clue about anything and they keep adding more gears to the network, some might even might at loss in the hope for BTC price to go up