One problem related to transmission pump has been reported for the 2015 Chevrolet Suburban. The most recently reported issues are listed below.
Car would rev, then shift very hard into gear from a full stop - either going forward or into reverse. Had also noticed some uneven gear shifts when go up hills and revving of engine prior to transmission engaging when on the highway. Taken to dealership, where I was told the transmission pump went out and would require the entire transmission to be replaced, which was not under warranty. This happened at 144,400 miles. However, the remanufactured transmission would be waranteed for 300,000 miles.