So is it a good news or a bad news? It is harder to obtain bitcoins, thus probably new investors would buy them, the price should raise.
Bitcoin price IMO is mostly unaffected by mining. When people shut off miners the difficulty drops. Even a smaller number of miners prior to a difficulty drop would process the transactions allowing market to perform as normal.
How many coins miners sell & when does have an impact. The scale of the market determining the resulting impact. Large conversions of coin to USD to pay for hardware might explain any weakening of bitcoin value from time to time.
However many people ordered ASICs long ago. When they receive the hardware, they will run it. Difficulty adjustment has some lag too.
Due to lags in ASIC delivery, difficulty adjustments and price fluctuations, it is quite possible that at some point mining won't be profitable and most miners will switch off their mining hardware after difficulty adjustment. So we'll need to wait hours for block to be found and months for the next difficulty adjustments. Higher confirmation time will move the bitcoin price down and make the situation even worse.
Is this scenario probable?
ASICs rely on low enough difficulty to recover purchase cost.
With low running cost relative to return most ASICs will just be kept running or be sold to someone who will run them.
Hardware investment is the issue. Miners will be expecting good returns. Ultimately if poor returns (an overall loss) this may lead to reduced enthusiasm for bitcoin.
A miner is less likely to invest in the coin or recommend it if their first recollection is of losing (meaningful) money.
Another issue is people who mine can be enthusiastic promoters. Those without the money for specialist hardware may mine other types of coin taking to promoting & supporting other coins instead of Bitcoin. This is the real problem if the breadth of the market (real world uses other than speculation) doesn't continue to grow.