Beaching of corals and coral reefs is indeed a huge problem, and unfortunately it will only get a lot worse in the coming decades. These organisms are extremely sensitive to both increase in temperature and acidity (lower pH), so it seems highly unlikely that the coral bleaching events will stop anytime soon.
I'm not sure how these mesophotic or the deep-water coral reefs will respond to climate change though, but hopefully it won't be that big of an issue with them since they are less dependent on the symbiotic algae.
I am afraid you are right about the prospects of the tropical corals :( Let´s see how these deep-water corals will do in future.
They probably won't be affected by bleaching at least, since they don't rely on zooxanthellae to do photosynthesis (these are essentially removed from the coral when it gets too hot, leading to a bleaching).