It probably isn't specifically designed for the wheel size change. Probably labelled that way because you cannot run the shorter chainstay with the 29. There may be clearance issues if you did.What I was saying was, I don’t think I’ve seen a flip chip in that position that is specifically to change wheel sizes.
As I said before. You can probably run the 27.5 on both chainstay lengths. But not the 29 on the short CS.