Thanks so much for the suggestion of botrytis.
Quick update:
I got antsy, couldn’t leave it alone, so I brushed the plants aaaall over with a 2% soap solution
My hope was this might do some good and maybe wouldn’t do any harm?
But, the odd thing was, I tried brushing the backs of the affected blooms (for the heck of it, and like I said, I was getting antsy) and all the spots came off fairly quickly/easily. Would this happen with botrytis? I did get a fan going nearby too for some light airflow and am moving it around.
Also, I just remembered. I was deadheading canna lilies outside yesterday. And I brought the bag in with the garden waste intending to put it in the compost but hung it over a dining room chair and got distracted. The orchids were on the dining room table.
Thanks again for the help!