IMHO, I have been though mergers and have watched many occour as we all have. I have not seen one of the major signs that usually signals a merger is ripe. HIRING. Generally, both companies suspend all hiring when a merger is imminent. Just my observation.
Back in the 80's USair was hiring continuously through the various mergers that occured with Piedmont and PSA. At some point during the transitions USAir was hiring and placing the pilots at either PI or PSA depending on needs within the class.