Thanks, I had been looking at this as mainly a light issue, but you're right about the moisture. I should dig into one of the baskets and see if something unexpected is going on there.
Most phals, and the affected ones, are in slat baskets lined with screen (so finer bark doesn't fall out). I generally put a "lump" of sphag on the bottom and cover with a layer of bark. The plant then goes on top of this, with the roots covered with more bark mix (contains charcoal and some coarse rock-like material). I've had good luck with this layering method for phals for some time now. The idea was to have a gradient of more moist to pretty dry, so the orchid could send roots where it was happiest, and also would provide a little extra dry-season moisture.
This year, with the abrupt change from wet to dry season (about when I moved them) it might have added to the stress of the move and light changes..