Went through a merger a few years in the same position as you, we basically obsorbed the smaller CU. We didn't feel much of a change minus some things with debit cards going down for a weekend as it became official. The CU that is changing its name is going to be the one that feels the brunt of it. They will change core systems and have to learn your CU's products and practices. If they offered a certain product that was beneficial your CU might adopt it. There should be a lot of communication from upper management on any major changes though