I'm guessing that this is strictly being done by the bean counters. It will save the company more money to downgrade 30 CA's than to furlough 30 FO's which we are short on anyway. This way the company saves money and helps cure a staffing shortage. They are essentially killing 2 birds with one stone.
The big problem with this approach is that should our marketing hours increase, there will again be a shortage of CA's and we will be back to canceling flights because of a lack of crews. This in turn will cause fines and see mis-managements bonus's disappear. In the short term the displacement might sound like a good idea to them, but it will eventually backfire on them and cost them much more money in the long run.