I recently repotted a Phalaenopsis orchid because Some kind of green moss started to take over the old pot (see the attached photo). Though the orchid was doing OK and blooming, I re-potted it before the moss completely took over. Hope I had done the right thing
It was fine. I would not have repotted based on the moss. In habitat many orchids grow on moist branches in mats of moss. In humid greenhouses moss grows on top of many orchid pots.
__________________ May the bridges I've burned light my way.