A couple of weeks ago at a meet up I was at. A CM who was part of it said that everybody's saying good-bye to the subs. Upper Management is takingaway the costumes.
Yes, but only for 3/4th of the year or so. Those costumes wont be used during that time so the CM can return them. When I was a CP at WDW, I was limited to a certain amount of uniforms, at least one for the 3 positions that I had. So why issue out an uniform that they will not be using, where they could have another set of uniform for the position that they will be working at. Having an extra set helps out on laundry, so you don't have to wash every day or spend time issuing out another.
Cast members don't know very much about high level decisions. Usually when an attraction closes, they are told that they are going to be relocated and that's about it.
Since this is a long refurbishment, costumes are returned because people tend to shove their costumes into their closets and they end up losing them. Having the costumes in Disney's possession allows them to clean them and keep the entire inventory ready for when they reopen.
As far as I know, they ordered the necessary parts to repair the attraction, which likely means that it's returning.
I don't know about you, but if I don't wear clothes for a month, I have trouble finding them. Now take that and make it 9 months instead of one. I've not been big on believing the subs are coming back, but a costume return is not an indication of that at all.