Can the difficulty increase once it has his miminum profitability without an increase in price? No, it can't.
But the price can fall, crypto winter can go for months (years?) and the difficulty won't fall that much, not proportionally at least.
There is no chicken and egg, the difficulty follows the reward, sometimes it might now keep up p with it but never has the difficulty dictated the price.
It was said in many occasions that the difficulty follows the price and it was said in many occasions that the price follows the difficulty sooner or later. So.. yeah...
It's a freak situation, simple as that, it can't be a perpetual state of affairs and its effects will soon be negated.
Freak situations, exceptions, .. name it. There are always cases to show that the rules don't always work. Isn't that the point of all this discussion?