I did receive this email yesterday which should shed a little light into the current goings-on:

The source is the main woman in Mecca:

"The ERJ classes will be small over the summer but the upgrade time will increase once I start sending pilots to class on the west coast.
You will see the CRJ classes reduce in size over the summer as well and the same thing, if I open up any domicile other than DTW the upgrade time will increase. But the majority of vacancies will be DTW for a few more months."