For reference, last spring (2015) when I was transitioning from EMB to CRJ, they came to the newhire class next door the day before systems exam and asked if anyone wanted to fill ERJ slots.

then when they didn't get anyone they came to my transition class of 14 EMB guys and asked. No one took them up on it. So I wouldn't discredit the poster. I saw this happen. It's crazy. that being said, once you're out of ground, they're not switching you. I have a few 175 friends who want CRJ and can't because of seat lock.