Years of data show that the correlation between hashrate and price is not very strong, there's a lot of wiggle room, and it's mostly the price that influences the hashrate and not vice versa, so there's no feedback loops like you are describing. "Mining death spiral" is like the oldest FUD in Bitcoin, and it was debunked on practice many times.
Simply comparing the price with hash rate is wrong because it doesn't take into consideration efficiency, A far more reliable graph would be that of the price and the hash rate based on an average th/w consumption.
Just look at the latest batch of miners, even with absolutely zero price increase, we would have had a jump in hash rate of 3x times with the change from the s9 to s19, the miners would have the same income, the same costs, the same profits but they would make 3 times more hashes. per second.
So an adjusted graph taking into account this evolution would picture a far more accurate view on this.
Anyhow, only 14hours to go, right now we're seeing 170 blocks in the last 24 hours, 26 more than expected so it's either that everyone is mining with whatever it has or new gear has finally hit its destination. If it's the second the drop will be far less than predicted.
Over the past week, according to data from ByteTree, miners held about 1,067 Bitcoin. Ostensibly, miners hoarding Bitcoin seems positive — but it is not.
Mining income in the last 24h was 2,125+59.04 BTC.
So, whatever this "study' has found it's a bit irrelevant