There's probably a major morale hit if you get thrown into training ("Oh actually you're not useful to us right now, go back to square 1"). Also now you're running a retraining program, which can be hard.

Now I think that if you're a large company, having this venue open, and letting basically anyone apply for retraining to another skill set is a good idea. But I think it's not obvious to execute, and involves a lot of risk.