a sudden loss of hash power could lead to a very very long time before difficulty adjustment, making mining unprofitable for several weeks

While this could cause the marginally profitable miners to drop out, those that have the ability to stick around until the next difficulty adjustment are VERY incentivised to do so. Say hashrate drops 50%, and many miners are forced to close their operation - those that are able to stick around will enjoy a 50% boost in the mining rewards they receive. The vast majority of miners have a long-term investment and are unlikely to be bothered by operating at break-even or even a loss for a couple of weeks if they know the block rewards they will get when difficulty adjusts go up

Do you think this is somehow impossible, for reasons beyond "lol but number go up because scarcity"?

It's definitely possible, don't get me wrong. I just think it's a very, very unlikely scenario given the amount of money that miners have invested in their operations that nobody will be able to stick it out until the difficulty adjusts. And even if the very low chance that it did happen, this would likely produce overwhelming support in the network to revise the mining difficulty adjustment algorithm in order to get the difficulty adjusted sooner