Interviewing with a former employer after a hiatus

Hi all; I'm a dev of about 6 years experience who took a year off to finish a degree, something I'd put off but really wanted largely for personal reasons. Right before I went back to school, I worked for a company that I absolutely loved. Admittedly it might have been a honeymoon thing as I'd only been there 6 months, but the culture, the tech, and the environment was awesome, and I left on really good terms with my boss. I'm about to graduate so I reached out to my old boss who explained that because of an acquisition, hiring itself was a bit out of his hands, but that he'd pass a referral along so that I'd have my foot in the door with the interview process, and that has come to pass.

I'm just curious if anyone has had a similar experience of coming back to an old employer and what the interviewing process was like: was the pattern of questions any different from normal? Any insights would be appreciated!